Been a while since I last worked on the BSA as the area it was kept in was not practical enough to undertake proper work. Now it is in a larger workshop where I can finally get a good run at it.
Replaced the broken twist grip, added some new rubber grips, managed to undo the gearbox filler cap so the oil tank, battery holder and toolbox are back on the frame. Just drained the oil and replaced the sump gaskets.