Hi Cider1
I think you might be looking at Gold star badges which wont fit an A10 tank being a bit bigger (4") although there may be a 3" available.
Suggest you google for classic badges or something similar , there used to be a company called something like " The classic badge Company" but I can't find them now, however new badges are available so some one must make them,
Try the trusted traders such as Burton bike bits and any of the others they might be able to send you in the right diretioc if they cannot supply themeselves
All the best - Bill