I've got it finished and shot it through my heaviest bows, which aren't really much over about 80# @ 32" but at least the arrow survived, they were sticking in at a slight angle, (nock to the left) it's pretty irrelevant with an underweight bow.
I'm not sure if the flights are too thin and flexible, it needs a proper test. The spine is only 75-80# so I think I'll make up the next two from higher spines. I'll probably fletch 'em with my usual commercial flights, but trimmed down to low profile with my hot plate feather shaper.
The nock end of the arrow has a rod of horn (approx 3.5mm diameter) glued down the centre. The end is tapered by about 4 degrees (too slide set to 2 degrees) a small flat is filed on each side and a sliver of horn glued on with rapid epoxy. The end is then bound with fine linen thread, low viscosity superglue is dabbed onto the thread and soaks in hardening the whole lot. It was then all sanded down smooth on the belt sander and wiped over with epoxy to make it smooth.
The ears of horn give a secure deep nock, but don't actually grip the string. the nock groove itself is smoother with a round needle file.
If I get 3 made up, we might get to test 'em at the weekend or one evening. (you reading this JT? ;-) )