I bought a replacement mask 8 years ago from a guy on RGP named MNpinball. It was made of a high quality 3M adhesive material. It was a great replacement for the missing silk screened mask. I think he is on Pinside now under the same name? I posted a copy of the thread from RGP, I hope this helps.
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As stated by others here the backglass is screened on both sides. The
mask and hangman are on the outside.
When the flashers are illuminated the mask area becomes translucent
and you can see the face.
Many times on location kids scratched the mask with quarters or other
items to see behind it thus destoying it.
I took a mint backglass to a screen printer and had this area
reproduced on a high quality 3M scotchcal opaque material.
Never had a complaint and makes it look as original.
POTO mask decals sold here: They are $35.
http://www.pinballsinc.com/forsale.html
Jason.
www.pinballsinc.com
