http://youtu.be/ZdGImbT3Evw
After getting it freed up and oiled, I laid the cabinet on its front on a towel, put the glass on very small globs of RV mastic (non-hardening) to have something between the glass and the metal- maybe not necessary, but made me feel better about it, and Re- installed the mech.
Still don't know what (if anything) will trip the big jackpot...As I said,
three bars only paid 20 coins from the payout tube, as per the payout schedule on the front.