*Cough*
Well. I got the 22mm Spitfire ARB, and I got the associated mounting kit and I got the polybushes - eventually. Then, before I took the ARB to be powder coated, I realised I had bought the wrong drop links, my fault entirely, didn't read the parts list properly.
Lovely aren't they?
So, being little more than a big kid really, I immediately set about attempting to trial fit the ARB.The holes in the ARB mounting plate to take the "U" bolt from the mounting kit were too close together by about 3mm, but what the hell? I am a seasoned TVR restorer now, so, rather than worry about this for too long I gave the "U" bolt a delicate tap with a hammer and it dropped into place perfectly. I was on a roll.
Except that the Spitfire ARB doesn't appear to fit the TVR Series 1 Vixen.
So its back to the drawing board
April 2020 UPDATE:
I had not thought about this issue for a long time until one evening bored in virus lock-down, i was browsing through some old photos I had downloaded from the net, of a Griffith 400 being stripped for restoration and I happened to notice what looked like a spacer between the drop link and the antiroll bar.
A bit more research and I found a series one Vixen with the same spacer:
So I think that's the answer. It looks like the car may have had a Spitfire/ Herald ARB with a spacer.
Having reassembled the ARB and checked it looks like a one inch (25mm), 3/8 ID spacer would do the job. So, just waiting for that to arrive!
Update: Yep that's the one!