Whether or not this is even possible depends on how the original wiring was installed. I'll outline that for your particular situation with old unidentified wires and NO Ground, and only two screw connections on the old switch.
The straightforward way is what has been assumed in the wiring diagram you show. I presume that came with the switch / outlet fixture you got. In that scheme, a cable from the fuse box comes into the wall mounting box and brings in one Hot and one Neutral line. Then a second cable leaves the box to go to the light fixture. At the fixture ceiling box there is only ONE cable entering (coming from the switch box). Inside the switch box the Neutral lines from both cables are connected together. The Hot line from the fuse box line is connected to one screw of the switch, and the Hot line feeding out to the light fixture is connected to the other screw. This way the switch acts to allow or not allow the Hot power feed to reach the light fixture, and the current flowing through the light can return to the fuse box on the Neutral line that is connected right through.
The other scheme reverses the order of where the feed lines in the wall go. In this scheme the feed line from the fuse box goes directly to the ceiling box with the light fixture. Then there is a second cable leaving the ceiling box to run to the wall switch box. In the ceiling box the Neutral line is connected to the light fixture, ideally to the screw that connects to the large threaded SHELL of the socket. The Hot line is connected to the outgoing Hot line that head down to the switch. At the switch box there is only ONE cable coming in (from the ceiling box), and both of its wires are connected to the two screws of the switch. So one incoming wire is the always-on Hot line, and the other return wire is the Switched Hot. Back up at the ceiling box that Switched Hot line returning from the switch is connected to the light socket, ideally to the screw that feeds the central BUTTON in the bottom of the socket (where it is hard to touch by mistake). In this scheme, the power from the Hot line bypasses the socket at first and flows over to the switch, then is returned after switch control to the socket, flows through the light bulb and returns to the fuse box on the Neutral line.
WARNING: In these old wiring systems, as you see, there may be no label or colour code on the wires in the two-wire cables. Moreover, at the time they were installed, many did NOT care which line is Hot, and which is Neutral, so they did not bother with colour codes. This means you can NOT deduce which wire is which anywhere merely from how they are connected to things. There's really only one way to identify properly, and this requires a long extension cord, a circuit tester, and some wall outlet somewhere that DOES have the three-prong configuration with a true Ground on the round central hole. If you have those available, FIRST thing you do on this is remove the fuse that feeds the circuit you are trying to work on. Then TEST the outlet AND the ceiling fixture with a volt meter to be sure the power is off at both places. If it is, carefully remove the fixture from its box at each location, but do not disconnect any wires - just pull the fixture out from the box. Make SURE it is not touching anything, just suspended in the air by its wires. Now re-install the fuse and recognize you have LIVE wires to be careful of. Now get out the long extension cord and plug it into the grounded new-style outlet. Drag the other end to your work site. Use the volt meter to measure the VOLTAGE between the ROUND Ground hole of the extention cord and each of the wires in the two fixture boxes. At each box you should find that ONE of the incoming wires has 120 VAC on it, and the other has zero volts. (This works becaue modern wiring uses a Grounded Neutral system in which the true Ground for the system is also connected to the Neutral bus AT THE FUSE Panel and nowhere else.) IF your wires are arranged in the FIRST scheme I outlined above, then you will be able to see which of the TWO cables in that box has one of its wires always Hot (fed from the fuse panel), and which wire going out to the ceiling fixture is Hot only when the switch is "on". IF the wires are of the second scheme above then at the SWITCH box with only ONE cable coming in, one wire will be Hot always, and one will be Hot only when the switch is "on". Similarly, at the ceiling box, you can identify which wire is which according to their voltages compared to that Ground hole in the extension cable, and the setting of the wall switch. When you have them sorted out and LABELLED, remove the fuse again and TEST to ensure the entire circuit is really "dead".
Now, what YOU want is to install a new device in the wall switch box that replaces the old switch. That can work ONLY if that wall box was installed according to the FIRST scheme above - that is the one that has TWO cables into it, and ONE of those is the direct feed of both Hot and Neutral from the fuse box. If that's what you have, then you can do this istallation according to the diagram you posted. The Hot lead directly from the fuse panel goes to the device's COMMON screw. The Hot lead for the SECOND cable that goes out to the ceiling box goes to the device's A1 screw, the output of the switch. The two Neutral lines from the two cables need to be uncovered and freed up. You will need a short third piece of wire about 6" long bared at both ends. Connect one end to BOTH of those Neutral lines, twist them all together and insulate - a "wire nut" is the easy way. Connect the other end of this new wire to the device's N screw. This is the Neutral line returning to the fuse box (via the cable neutral lines) the current from any device plugged into the OUTLET part of your new switch / outlet device. Check all your connections and ensure they are insulated, the carefully push the new switch back into its box and fasten it in, then install the new cover plate it requires. Similarly, at the ceiling box, re-install the fixture. Re-install the fuse and verify it works as it should.
On the other hand, IF your system is the SECOND scheme with only ONE cable in the switch wall box, and TWO cables in the ceiling fixture with one of those directly from the fuse panel, then you can NOT install this new device you want in the wall box. That is because there is NO Neutral line into the wall box, so there is no way for current to flow back to the ceiling box and then back to the fuse panel. Now, SOME such layouts in modern installation have been done differently using a cable between the ceiling box and the wall box with THREE wires in in - Black, White, and Red, plus a bare copper Ground wire. IF you have that, post back here for a different approach. But I doubt you have that - it was NOT common to do that at the time those cables were installed decades ago.
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