Hi Steve!
I'm sorry I haven't been following to closely, these are busy times.
Regarding the ann* file, it seems to be an annotation, and I guess the serial number is put there to make it match the originating device.
/fridge is just a link to /intstorage, so it makes sense they have the same stuff. Once the library is set to external, I don't think any of the files in /intstorage matter anymore, only the ones in /sdcard.
Regarding my suggestion to change the serial number, you don't have to keep the old one forever! Once you restore the library (which I would hope would work), change the serial back to the Allmine one and apply the "Library fix" by hand. That should fix the library, and keep access to the market.
I did not know about the office... If you change the device in the build.prop file, you'll probably lose access to the market, though. Maybe you can switch the device depending on what you want to do?