65 Valiant Refresh

cool car. glad you are having fun with it cause that IS what its all about. glad to learn about the Sintra. I can see using that myself.
maybe this will be a car for your daughter in bout what 14 yrs!!????
you might clean the loose rust off floor. a wire cup in drill or right angle grinder works good, or elbow grease and wire brush to. lots of things to combat that old rust. driver? go to auto parts store, get the rust convertor, after it does it things, put couple of light coats of any good oil based enamel, ( too heavy and it takes forever to dry). some people put bedliner over that.
keep us posted on progress on the refresh. and have some fun....