"noOS" means that the firmware in ROM fails the bootloader's checksum test.
Typically this occurs upon restarting the BCR after an incomplete upgrade operation: some parts of the firmware have been renewed, others haven't, causing the checksum failure.
The only way to remedy this is to upload the new firmware completely via a cable connected to the BCR's MIDI IN port (the BCR's USB port doesn't work).
(Incidentally: just try the 1.10 firmware; it's no use at all trying 1.07: if you can't get 1.10 to work, the problem lies in the procedure, not in 1.10 itself.)
If you use BC Manager's bi-directional firmware upload method (from the B-Controls window: MIDI -> Maintenance -> Send firmware), you must also connect a cable back to the computer from the BCR's MIDI OUT A.
However, if you use a one-directional SysEx uploader, it may be best to REMOVE the cable from the BCR's MIDI OUT A; the uploader might actually get confused by the acknowledgement messages returned by the BCR during the firmware upload. (In fact, this might be the reason you've ended up with noOS in the first place, particularly if the BCR's Operating Mode was S-1 or S-2.)
On a side-note: it's a pity you have (partially) overwritten your 1.04 firmware: I'm a kind of "old firmware" collector, so I would have been interested in capturing your 1.04 firmware (yes, that's possible!) before you upgraded to 1.10, but alas...
Anyway, good luck!
Mark