I put it up on the tiller and pulled it back to 24" with a good deal more confidence now the bend is more even. A very pleasing 45 pounds.
A bit of tape round one of my arrows at 24" to avoid overdrawing allowed me some test shots, it seemed pretty fast, but very hard to tell.
So I set up the chrono' and cut an old arrow down to 24" and stuck on a 70gn point.
The results are a bit variable as it's hard to get the real maximum draw and a clean loose. the first tentative shot was a disappointing 151 fps... then it got better.
All pretty impressive. I'll be popping into Quicks the archery shop at the weekend, I'll buy some 9/32" and 1/4" shafts to make up some flight arrows to try it for distance.