TR7 handbrake lever looks suitable, I was looking for something similar with a single, central cable connection. Early mini ones looked like a possible candidate but from memory, they were a bit flimsy. I'm hoping the VW Polo one will be a bit more solidly made.
The verdict on my Honda radiator idea is so far so good. I haven't had the chance to take it out for a proper run yet but I left it idling in the blazing heat for half an hour yesterday and it kept the temperature gauge in the mid range with the electric fan running. There were a few teething troubles on first run up to temperature - the Honda radiator cap had steam bubbling out from under it shortly followed by more steam from the Triumph one on the in-line filler, but that seems to have been them just bedding in as they haven't done it again. Plan B is that I made my shroud big enough to take one of the Civic alloy racing radiators if it does overheat.
http://www.ebay.co.uk/itm/HONDA-CIVI...item519f7efb05
Cool.