There's not a lot of metal available for early A's but Auto Body Specialties in Connecticut has floor pans listed for your Valiant. You have to look under the Barracuda section.
The floor pans from Auto Body Suppliers are very good reproductions. I used both fronts and the right rear in my 65z. With some minor trimming , they are nearly a drop in ready to weld. Shipping to VA was not hateful.