I applied PPF under the belt (to my now sold Morgan), with no issues with marking the paint.
That's a keeper Craig! I will put it up on GoMoG if you don't mind.
I too love Morgan bonnet belts..as much as I love low down torque.

30+ years ago I would regularly scratch my bonnets trying, no LINING, and EVERYTHING else. Nothing worked so I kept having the cars' bonnets resprayed every year
. Quebec winters give one time to cure everything.
After a time, I began having my belts made by my wife's tack person...(Audrey is a horse/people trainer and whisperer). That tack person turned me on to something that also works. Persian Lamb, that cheap fur substitute our great-grandmothers used to use. The tack person bought me some, lined a belt, and I haven't had a scratch on the car since, nor the others I did the same with. I bought black, but I see all earth colours in Persian Lamb up on ebay.co.uk
Lorne
https://www.gomog.com/allmorgan/buckle.jpg