Hi Clayton,
I have some E-bay carts, which may differ from the MIS carts. The physical carts for the R280 and 1400 appear to be identical in every way I can see. The chips appear to be different, they have different part numbers referencing the 79/78 series. I haven't actually tried switching them, but I suspect the chips are in fact different. I can't see why the cloners would make two different chips if they didn't have to!
Sorry I don't have more specific details.
Ken