A few days of thoughtful tinkering has eased it back to a low brace with out too much sideways bend or twist, and I've had it back to 60# at about 22". I think we are aiming for 60# at 28" with some overdraw to 30" or so for longshots, warbow style shooting and clout etc.
It would have been good to take some pics of the sideways bend, but I didn't want to leave it on the tiller for long in that state. The main cure has been moving the nock on the upper limb sideways by about 1/4" and easing off the belly on the stiff side. If you picture the bow as square cross section with the back of the bow as the top (e.g Like it is on the tiller) I've been shaving away at the bottom corners as appropriate. At one stage I had a bend one way at mid limb and t'other way near the tip.
It's a bit of a catch22 situation as you don't want to bend it back too far while it's missbehaving, but bending it back at a decent brace height will help it come back straight.
As an example a reflexed stave braced to just an inch or so can easily try and flip up the other way on the tiller and whack your knuckles, but once it's pulled back about 10" it will sit happily.
It's now back to 60# at 24" and you can see how it flexes in the video, there's a nice bend over the middle portion but the outer limbs are stiff. Hopefully now it's coming back straight I can reduce the outer limbs without it all going sideways on me.
Update:- Blimey it's hard work, taken a good amount off the outer third of each limb and shortened the string to full brace, it's now 60# at 25" and the curve is looking better, but I've had to work to keep that upper limb from wandering.
Bit of a breather now, but I expect I'll have it back to full draw by tomorrow