From the front brake it looks like a 1970 model. It is hard to be certain if it is a single or a twin!
Tricolour sticker on the side cover was appeared in '67 and seems soon changed -> '67- BSA By checking the enlarged pic, headlight stay is black -> not the 'Lightning' letters on the tricolour sticker is reached to the screw -> not the 'Royal Star' = '67 BSA Thunderbolt (wild guess? )