If you have got a Cherry MY keyboard, snap off all the switches and sand the bottoms. Then you could glue those onto a flat sheet. They are not perfectly 1×1 key sized at the base, but almost.
I have flattened quite a few of Cherry MY switches myself for building keyboard prototypes and testing out layouts.
I have also got a couple of fridge magnets made from MY switches as a gift from another member.
I also seem to recall a special contraption that was one piece of plastic with lots of stems on them but I can't recall what it was, sorry. Hopefully, me mentioning it will jog someone else's memory.