Using my flatbed scanner, I scanned the whole playfield in, since this is probably my only chance to access it completely flat
I'm hoping that I can stitch these together and use them to update my CAD drawing to match the hand-changes I made when assembling, though I've heard mixed results about how accurate this can be...
Then I put down my sheet of plastic, which I think is 1/32 lexan, and started marking holes for posts.
The main worry with this plastic is whether it'll bubble and expand, separating from the wood, which I've seen happen when trying to make playfield protectors. This is a bit thicker though, and lexan, not PET-G; I'm hoping one of those two factors will fix that issue. To test it, the best thing I could come up with is just to heat it up for a long period of time, so I set it up with a bunch of incandescent lamps pointing right at it, for lack of any better options
I'll leave this on all day, and see if the plastic rises up anywhere. If not, I'll proceed with cutting the rest of the holes+slots, and reassemble the game for further testing. Not sure if I'll also cut the hole for the screen at this point, or play it some with the protector first before going 'all in' and cutting a 10" hole in the playfield.