Thanks but it wasn't it 🙂
It was well after the fuser that it was jamming, it has paper binning ability and was jamming in the paper sorter.
Found a lever that had a bit of crap lodged into it, removed it and she's working at full glory!
This printer is about 1.5 metres tall off the ground, 2 metres wide, 1 metre deep and weighs around a hundred kilos..
It has a world class resolution of 300x300 DPI and spits out 20 pages per minute 🙂
Well I guess it was good for 1960 when it was made 🙂