Here's a link to what is available on Ebay !
http://www.ebay.com/itm/KISS-Pinball-Machine-Playfield-Overlay-UV-PRINTED-Clear-Inserts-DIE-CUT-/302245115239
Looks that they are printed on clear vinyl allowing for playfield insert lighting. Personally I have seen a 'KISS' overlay before and they do look good.
I have successfully scanned small areas, created artwork in CAD software and printed on clear vinyl in the past to repair areas. Would be a challenge and very labour intensive to create the artwork for a full play field layover. Not sure how you would go with copy right with certain pinball brands.
I'm sure you would create alot of interest for selected titles. 
That link is exactly what I was thinking of doing. My retail would be about the same after costs. I don't see a issue doing pin companies that no longer exist.
