I think you should 1st make an image of the hd and please don't use it until that.
I can lend you my spare MFM Reader/Emulator. The BBB is the one with only 2GB of emmc but for testing it is enough.
I'll write a short howto for you to read and then emulate the hd until you have your own hardware.
Yeah, I didn't plan on doing anything besides browse the hard disk, but I won't be able to use if at the moment anyways. I think it was a fluke, random chance. My PCB's I had made for the MFM Emulator (the same one you are using), should come tomorrow. And then I will be building it soon, so I don't think I need yours. The only thing is that I only purchased the parts listed on the Mouser BOM, which didn't include a few things like the extra memory chip, and cables. I'm hoping that it isn't necessary for what I need to do, based on what I'm reading on the site.