Early Abody Sheet Metal Replacement Parts Availability?

I guess I should know this already, after having purchased by first ABoty in 1973 (1965 Valiant four-door) but I don't. What body panels are available in the aftermarket these days? For example quarter panel, door skins, front fenders, cowl, floor and trunk pans. Or is it up to the fabricators to make due with used parts? Thank you.

P.S. The reason I ask is because a potential buyer dropped by for the first time to look at the vehicle I listed on ebay and marketplace and he wanted to know.