you buy stuff regardless, why would he make a button switch if they were sold and also used by the original prop maker?
What does that little red button do?
It's not that he bought a switch INSTEAD of making one, it's that he bought the replica switch after already putting in the work to get the other one and presumably had it installed. Just seems odd to me to throw out your personal effort for something that's now off the shelf (a specific shelf but a shelf nonetheless), but I guess if you want it to be dead nuts accurate that's the way to go.