Good evening Adam, Bob and Stewart,
Delighted to read that 'patina' and 're-cycling', along with 'bush engineering' are still alive and well on this site.
Having lived with my 450 since '76 and carried out numerous 'alternative' repairs, often with advice from others more knowledgeable in engineering techniques than I, I think we all bear similar scars!
With a taper that looked as though it had been attacked with a cold chisel, a sheared woodruff key and deformed keyway and circular gouging on the shaft where the gear sat on the shaft, I didn't think graunching the whole lot back together, with more torque and 'Loctite' was a good idea. I had also shortly afore this had the mentally scarring task of trying to dismantle a Duke motor that had let go in similar fashion to mine and had been 'rebuilt' using a bastard file to remove the 'rough bits', Loctite 'Stud lock' to hold it all in place, on the taper, keyway, between the gear and shaft and on the nut threads. It took heat, pipe freezing spray and 3/4" drive air hammer to part the bits!
Whilst I'm content to use 'alternative' parts, I try with my limited ability to keep the mechanicals safe, I have lost to many friends to mechanical short cuts or expediancy. A good wash with a reputable shampoo and then some wax polish once in a while is about as far as my concours finish goes. Trailering an 'immaculate conception' to shows; well, all the best, it just isn't my idea of fun.
Dave Roper's blog and machine preparation seem comfortable to me.
What ever you do Adam, I trust it serves you well and you can get out and ride the wee beastie. Bob, thanks for moderating the site and Stewart, I hope the 450 is still with you, as mine is with me.
Slainte, Bill.