I always meant to make an alloy butterfly to hold the back of the bonnets vertical instead of using metal props, but never got round to it. Maybe I should make an effort. Leather or neoprene would protect the paint.
Years ago I used a centre chrome metal pole under my MGB bonnet. One day at an event, the wind lifted the bonnet and the pole came down over the offside front wing. You couldn't see the dent, because it matched the pole diameter. and was very slight, but you could feel it. After that I tied the top of the pole to the catch spring so it couldn't drop.
