Looking on the BSA Bantam Club's website it seems I need a new centre stand stop plate (which is also the brake pedal stop plate), and I've found one on Ebay which I've put in a bid for. Six days to go!
The chunk of iron I included on this blog yesterday was originally the stop plate, but had been added to by someone over the past 62 years. So it's now up to me to put it back to its factory state - if I can! There's more fun to follow, no doubt.
In the meantime, I shall still be riding Little Willie as she is so well-loved in my home town. So more of the D7 Bantam later!