If your bike is a 61 it's the front hub that's wrong. Alloy hubs only 56-57.
The swingarm is a little different for the alloy hubs. I have spare hub & s/arm but postage cost would be ridiculous.
Thanks for the info. I reckon the A7 is a mixed up old girl - 57 and 61 ! I had some issues a few years ago with our DVLA when the annual test procedure tightened up and frame/engine numbers were required. It transpired that the frame number registered had long gone, presumable someone smashed the bike before it came to me and switched frames.
I had the 'new' frame number verified by our UK BSA expert who came up with 57 as the year registered but I was very keen to keep the registration number for the 61 bike 777AWA and won my case so who knows what bits from what vintage ended up being my cherished A7 ?
Thanks for the offer of hub/swingarm which I would have gladly taken you up on but I'm sure you're right that the postage would be prohibitive.