"So... my recommendation is to look over schematics for differences. I think there are some." I have some RM03's and a 9762, and this matches my understanding of these drives also, in other words one or more of the cards in the RM drive itself were modified, meaning that the MASSBUS interface doesn't connect to the drive over a standard SMD interface. These cards (in the drives) are not very large or complex, I'm guessing it should be possible to identify the differences. Also please don't discard the MASSBUS adapters - they're probably of interest to the community!