Glad it`s not just me then....... Same problem exactly, the oil tank unions are silly close to the frame tube on mine, and the hexagon of the rocker feed locknut had dug a triangular pit in the tube whilst merrily vibrating against it.
I dont think BSA really thought these things out too much/ at all?.It must be the silliest,costliest, most complicated way to do the simplest of jobs, and succeeds only in being er,um, weirdly CR_P! What were they thinking of.......... ?

The curved ,slotted bracket on the back of my tank itself is welded on too high/low (cant remember which) resulting in it being a mile from anything like reasonable alignment with the front mount assembly........ and the whole sorry, complicated plot finally relies on chunks of rubber wedged between the frame and the tank.....I`m surprised BSA didn`t just stuff rags in there!!!!!
For years I have puzzled at it thinking,"what have I got wrong" but no, I had it as BSA intended all the time....... The Japanese must have been mystified........Best of luck, Bob C