Quoted from Bortino:A Flip-A-Card that led a hard life
Flip-a-Card is a great game. When a local 2nd generation operator sold his business it was the one machine he kept for his home game room.
That brown stuff looks like some kind of glue residue left from a fabric or paper or vinyl covering someone used to "dress up" the cab. Maybe you'll get lucky and it will come off with krud kutter or similar product.