Hi Mike,
I agree totally, re. bolt heads and Unified or Metric used on older vehicles, they stand out a mile, but BSW against Whit are not quite so bad and at least it keeps the thread form to a standard. On my restorations, I endeavour to keep to BSF or what ever it might be on the particular vehicle, but things like wartime Bedfords and British Fords can be a bit of a mongrel when you look at them, bodywork predominatly Whit, whilst NF and NC on chassis and running gear. Coming on later, the Land Rover 90/110 was still using BSF threads in the axles, Unified threads in engine, etc., and Metric elsewhere.
Your comments on spanner sizes is true, the amount of people who think, for example, a 1/2" A/F spanner means that the thread is 1/2" .
But.......what is more infuriating is not using the correct spanner for the nut or bolt. I have observed many using Metric or A/F on Whit, BSW or BSF and not even having the correct spanners for their vehicle :shake: :nono: no wonder the corners are always rounded off :-(