The half-size coin mech in your V80 is electrically & functionally compatible with a CoinCo 9800 A/B series/120 volt mech. I assume the vending relay is a physical location problem (possibly) , is it possible to relocate it a tad if necessary? I haven't worked on V80 in a long time, can you possibly post a picture?
PS the free-play switch would work fine, although the connection from pin #1 to #7 may not be necessary.