What's the best way to proceed

You are having way too much fun, Chris

Regarding the securing pins - Ive used 6mm carbon pins on my much heavier Supersport for >10yrs now, so 4mm on this light model will be fine.

Furter to your Silver steel wing joiner - Bear in mind that although this material is much stronger that mild steel its "spring" characteristics are limited compared with music/ piano wire. An alternative would be carbon tube which you could safety by inserting a piece of piano wire in the centre.

Chris sorry to hear of your problems, but I now have one of my own.

Having read your last post I have lost the will to live.

That's encouraging Jon. I sat in a darkened room when I read about the wing joiner problem. Nice to know I'm not alone. I think the "seizing" is caused by the lapping paste. Perhaps swabbing out the bore of the tube with some dry tissue on a dowel would help.

Thanks for the tips Kevin, I was in part making do with what I had to hand, but also not making the best of decisions! And I'd never have thought about making a "D-bit"

I went with the silver steel, as I was just tying to replace like with like, but will experiment with CF tube at some point.

Mike, I am having too much fun, all of my own making too

Jon, my condolences on your current predicament, I think it says a lot about your kind hearted nature that you take such an interest and empathise so deeply when you hear about others misfortune. :evil:

Re: the use of 4mm carbon fibre pins ... i would recommend roll-wrapped tube as it is stronger in all planes compare to poltruded profiles.
Roll Wrapping: involves the applying of resin pre-impregnated composite fibre cloth (Pre-Preg) around a mandrel. The outer diameter of the mandrel thus determines the inner diameter of the final tube. The mandrel and cloth are then spiral wrapped with a consolidation tape under tension to hold the laminate in place during the curing phase. After curing, the mandrel is extracted to leave the tube ready for machining or finishing as necessary.
Pultrusion : is a process in which dry, continuous fibres are pulled through a bath of resin and then through a die. The die serves two purposes: it forces the bundle of wet fibres to conform to the shape you want to create and, since the die is heated, it will cure the resin to set the bundle of fibres into its final shape. After the composite comes out of the die, it is allowed to post-cure while being pulled to the saw where it will be cut to stock lengths.
Quick someone fetch the de-fibrallator, I think Jon is slipping away !!!