Received my boards and they look good.  See pictures below.  I had one small error on the cartridge board - I connect one too many pins to ground.  There are only 3 ground pins, and I connected 4 somehow.  I had to cut one trace.  I have only tested power and fit.  The drive did not work when connected, but I didn't insert a USB drive yet.  I also haven't flashed as better firmware yet - my plan is to load FlashFloppy.  That's up next.

I haven't installed the drive swap chip yet.  I want to make sure everything external works first.  I figure if I can get it working as a B drive first, then swapping to an A drive will be easy.