Same here.
And the part that irritates me most is that it shouldn't be a difficult feat since you just have to dump the memory chips, look for and isolate the hacked ROMS and replace them with ROMS of the same size or smaller (padding the smaller ones should absolutely work fine).
I don't have the tools to dump (nor knowledge, for that matter) those chips, but the process should be quite straightforward.
I'd do this with a 138-in-1 since it has "good" roms (the 161-in-1 has modified roms to work with the 1P+2P trick to get back to the main menu): dump the chips, use any tool to look for the data of known good ROMS and isolate them, so you know at which address they start and at which they end. This way you've isolated the hacked ROMS too. At this point, just replace the hacked roms with good ones by swapping them with one of the same size or smaller and pad the smaller ones so that they end at the same address as the previous one.
Again, I have mostly no knowledge about how NeoGeo accesses data on a cartridge, so I might have said a bunch of nonsensical things, but, hey, we gotta start somewhere, don't we?