Although BBC-B computers are not rare the add-on boards inside this machine seem to be extremely rare.
Both are made by the Computer Village. The floppy disc controller (double density) is a 1797 FDC which was an upgrade from the original 8271.
The disc operating system is LVL DOS which is held on ROM.
The second board is a Memory Expansion Board which I believe has battery backed Sideways RAM and allows expansion of allowable ROMs.
I have PDF images of the manuals for both boards and will include these on a CD.

I have not tested the computer fully but it seems to boot as normal (as can be seen) and gives the normal bee-bop.
It has been refurbished and is cosmetically very good.
The power supply had new Capacitors installed in 2019.

This sale only includes the computer itself. No leads or monitors are included.
As this computer is over 40 years old there is no guarantee of functionality or that it won't self distruct in the next five seconds.