Someone came to me with this and wanted some information on it:
 

I would have to rule against it being a prototype
1) early gyromites were on famicom adapters
2) there was no localization done to this game the title screen still reads gyrobus
3) it's not a Dev board or label

Could be a refurb or a custom repro although I don't know who would want to repro it

I'm guessing repair.

Doesn't look to be a proto. I'm guessing a repair or replacement from misc parts.

Factory repair, I've had nearly a dozen pass through my hands just like it.

Aha! I thought it looked unusual and wasn't a prototype, but I wasn't 100% sure. You'd think I'd have come across one of these, but alas not yet.

Thanks for the info guys!