Love stuff like this.... I don't know exactly what this board is, but reading up on the company that made it shows they made conversions for existing boards (you may already know all of this!).
I found reference to a racing game conversion for Galaxian and Pac Man with that same tan box and chips jumped with wire on it. This is that game. Maybe someone knows the others this company produced to narrow it down?
Edit: Hewitson and I must have been googling the same stuff, but unless they started from a bootleg Pacman or Galaxian I'm not sure its that racing game.