Hi Steve,
It looks as if the PO was a serious rider ???? ????
The QD rear wheel and rod brake gives a much better brake than the crossover shaft and cable
This type of wheel is also lot lighter than the full width iron hub
The solid swing arm pin is a smaller dia than the hollow one ! so has the frame has been modded to take the smaller pin??
The 8 inch single sided front brake is regarded as the best that BSA made and yours appears to be the iron hub with the vent holes , much sought after
If you were to revert to the standard A10 setup you would also need different fork bottom legs
The parts fitted to your bike are very sought after by those building RGS lookalikes
So why not dump the nacelle and fit chrome shrouds and headlamp, or even gold star type headlamp mounts??
The bikes modifications form part of its history !!!! and thats to be commeneded in my opinion
Regards
John