Bloody hell, thanks Paul! You've gone above and beyond - thanks mate.I'll give BSC a shot, but I doubt my chances there. Your suggestion will be a goer I'd say.
Whilst on the topic of BSC, I managed to pick up some accurate sint wheel bushes to suit tin wheeled Rotomos from there a couple of months back. Not cheap at $8.00 a pop ($16 per wheel), but they fit perfectly and match the originals precisely (1/2 X 5/8 X 3/8). You'd probably need to order ahead as they aren't stocked very often. Part number is C1620-5.