Well, yeah, this is very interesting because dr. mario is MMC1 where this is nrom (no mapper). So either it changed in development, this is a pirate version (many multicarts are just a collection of simple mapperless games like nrom), or ???

And what's it doing on a US board when I would think the game was developed in Japan? Was it developed over here? Did Nintendo actually buy the game from a US developer and not develop it in house? Did it just have a complete name change/turn before release? Did they make it as virus but then decide it wouldn't sell as virus?

The idea that it's a fake because it's on a non proto nrom cart--well I don't think there is a proto version of nrom circuit board. And Nrom was alway eprom compatible so there isn't a need for an e-nrom (nintendo proto boards for the nes started with e to say they were eprom boards rather than rom).

How interesting! Can't wait to see how this plays out!