I've a funny feeling I can help. "they" do not call me Steptoe without reason. I can still find a 16K Tandy computer around the place so a mere disk drive should not be a problem.
The issue is however that the drive concerned at attached to a PC - be damed if I can remember which one - and the PC is one of 3 lurking "somewhere in the loft". I saw it recently because I am in the process of putting a floor down in the loft . . . . and tidied the 3 computers away somewhere under the eaves to give me room to work.
I know I also found a bag of 5 1/4 disks and at the time thought to myself "must run those through a PC and see what is on them" and shred those with any personal info. Many of them will of course be 5 1/4 disks for the old BBC machine you now have
I will try to find time to get into the loft soon as poss and will let you know.
INCIDENTALLY - I thought one of the 5 1/4 drives you received with the Beeb had been modified (jumper change) so that it would run on a PC. For sure I ran one of those drives on an Amstrad in the late 1980s
5 Precepts of Buddhism seem appropriate. Refrain from taking life. Refrain from taking that which is not given. Refrain from misconduct. Refrain from lying. Refrain from intoxicants which lead to loss of mindfulness