Yes. Most things other than the engine and gearbox are BSF.
It’s mostly BSF rather than Whitworth (the fine rather than the coarse thread - and to add to the simplicity a Whitworth marked spanner fits a BSF bolt a size down).
Small fasteners are normally BA - I found a 2BA hex spanner very helpful with some old seized nuts. (And that will I think be the one you struggled with?).
This is helpful -
The Classic Mechanic: MM, AF, BSW, BSF Spanner Conversion Chart
There are a lot of 1/4 BSF bolts that take a 3/16 Whitworth spanner - but this shows that a 7/16 AF would fit.