Time Tunnel
Bally's TIME TUNNEL was developed in February 1971, but the new coin-door, introduced in early 1972 with FIREBALL indicates that production did not start before 1972. The predecessor MARINER from November 1971 still had the older black front-door from 1967.
It didn't reach serial-production because of legal problems and was redesigned as SPACE TIME and TIME ZONE.
Only 70 test-samples were produced.