With Taito - quite Often the Upright version of the game would use a 19" colour CRT, but the cocktail version would use a b/w monitor. Thats why Space Invaders has 'color' versions of SI and SI part 2. b/w crt's were more plentiful and cheaper and cocktail were aimed at a slightly different market to the uprights, so that business model made sense for the time period where parts/demand made it viable. The engineers just made sure the game could output both video formats so one pcb worked in both cabinets without any or minimal differences in production.
The pcb you have looks a lot like Zun Zun Block, i had one once along time ago.. should be all TTL, but has some interesting circuits to display text. I definitely pulled one out of a table that was black and white with overlays, its possible the pcb had RGB colour output, but i dont remember finding that when i hooked it up on my bench, or i may have made the adapter with RGB insted of just b/w output.