Did those particular cards have the double battery setup? (backup battery that holds the data while the main battery is replaced) or is it just expected & understood that the data must be copied to another card by the user prior to a battery replacement procedure because it is understood that all data is lost during a battery change?
Also, were you ever able to ask any questions to the seller? Such as trying to track down the history of the item like where the seller sourced it, from whom, and if there's anything more to be learned or had from its' past owner(s)?
Can't wait for Raz to have a look at the data. Not just to see if more of the game can be found and recovered, but more so to see if we can find any evidence of the licensee and game title. Also, maybe analyze the Voltage Fighter rom sets as well to see if any patterns or similarities are present in lines of code.
I'm still amazed at this find. Absolutely stunning. And those backgrounds are breathtaking.