Someone needs to scan at 2400 DPI and line detection turned on, and do it black and white, gray scale and full color to find out which works best for him. Or at least that is my honest opinion.

The issue is simple. Take the archway off (9x long screws as I recall), move a portable (hp type see through) scanner or invert the archway to a standard fixed bed 2400 DPI scanner (without interpolation) and run it, then send the files (scans, 3x) to Inki in b/w, g/s, and full color (24+ bit) and he'll do the rest. Someone can take 15-20 mins to do this, and Inki will do the rest. And then it will be done right, and done for eternity with vector graphics, and printing at infinite resolution, not raster and interpolated/guessing. Who steps up for the scanning? we all are the winner!

Wouldn't that be great to simply have the file as PDF with the 'Title' and 'Serial' numbers as PostScript defined text objects, rotation, offset by pixels, and let folks edit the file with pertinent text for their own needs so it doesn't look like every single one that is printed out looks the same. Maybe with shades of RGB changable as well, for various 'aging effects'. Possibly a 'screen' or 'alpha' that makes the entire thing look aged by a RGB with alpha defined? Maybe a simple tutorial file to go along with it, how to open with a text editor, or how to use 'vi/ed/vim/emacs' as bonus HOWTO.txt? Oh god, this would be classic 'raising the bar stuff', a new for pinball hobbyists. Inky, btw, you do AMAZING stuff, contribution, and dedication, for years!

With maybe a dozen or so per maker of models certificates, there
is a simple way to generalize this with PS's transformation and
ability to deal with alpha. Aside from 'fraud', which is going to happen
regardless, you are best to use the tools in PS to make a generalized
file and tutorial file to edit the transparency of the overlay over the green
(or other colors) for aging, then rotation for stamps, and finally do it
with scans that are of the highest quality. Google the PS Language Reference
for details on the image model of PS.