This has always been a post that sits in the back of my head every time I help someone identify a cabinet and I have never been able to find out what it originally was but always looked every once in awhile, until finally I saw this post out of nowhere https://www.facebook.com/As-Found-Arcade-Machines-671138093218203/photos/pcb.1391117444553594/1391117334553605
It appears to be originally a Gametecniks Tri-Pool arcade machine from 1981 with the only difference being the coin door, which very well could of been swapped out with a new piece of wood judging by the plywood instead of particle board and the monitor being turned around during the conversion to the Taito games.
Edit: The Quest is over