Hey Chris,Yesterday at GEH I actually got to lay eyes on an old Kodak perforater ...... in the labs down here I've come across these two little film splitters with stickers that say RIT on them. They are for splitting 4" film down to 35mm, and the other is for splitting 35mm down to 16mm....
Could you snap some pictures of these gadgets? It would be great to see what they look like.
Now, as far as punching is concerned, making a small punching block may be harder than you think. One of my projects that has held up my emulsion work was trying to punch 35mm because that is what I ultimately want, too. I was trying to punch acetate with 6 pairs of holes spaced for 35mm. Have not yet tried PET but I would expect it to be harder to do. Issues I came across:
1) Quite a bit of pressure is required to punch more than about 6 holes so you need a fixture with some leverage. I would expect PET would need more pressure.
2) Hanging chads are a real problem and they are hard to avoid without having to cut them off manually. Chads may be less of a problem with PET.
3) Round holes did not work reliably in any (Pentax SLR) camera I tried. Lot's of problems with jamming. You need a rectangular hole but I don't think it needs to exactly match the ANSI spec. There is some tolerance.
I had no real machining tools to do this and was just working with a dremel tool, nails (with the point cut off and then modified with a v-notch in the face) for the pins and aluminum for the die. So, I am not saying it cannot be done, these were just some issues that I found.