Yep... that was exactly what I was going to do next. There is an excellent engineering firm nearby that I have used for many things and they will be my first port of call. Plus I've being thinking it may not be a case of simply one bent leg but the perhaps the whole caboodle might actually be twisted somewhat. And, as you say, it's not summat to be resolved at home in a garage. See above - & besides I'm not entirely sure Brancato engineering is still going.
Now I've calmed down a little I revisited this measurement and it is still out but nowhere near as bad as I first thought - 1mm tops. Not sure if you are aware but the swingarm pivot is mounted in a pair of eccentric casting that are themselves fitted into the frame. Rotating these castings moves the pivot backwards/forwards & therefore the complete swingarm to allow for adjustment of the chain tension. Initially I was measuring from the split in the casting up to the mount hole but this time I measured from the bottom side of the actual pivot up to the bottom side of a bolt in the mount hole. And using a much better stick it has to be said...
