>>35743288STOP.
The guy who had it most likely never even realized what he had.
It was saved on an EPROM that said "Dr. Mario" on it, and it was probably in a shoebox with a bunch of random EPROMS and wired and other boring looking shit.
If the guy in question collected this sort of stuff, he probably saw DOZENS of similar pieces of equipment, there's notihng about the cartridge that screams ONE OF A KIND PROTOTYPE OF POKEMON GOLD.