I did note that the desk serial number ended in 0002 so that ties in nicely with your answer!
Although the disk utilities displayed the file, I wondered if formatting was the problem. I re-formatted the disc in the desk then loaded the OSF from pc. Lo & behold, this time the software loaded & everything looks just like the handbook! Many thanks for your reply.
(I used to work in Sutton Coldfield, wife came from Harborne. Small world . . )