I pulled out the back seat of my '64 Impala hoping to find the build sheet under the seat. No luck, No build sheet. I did find some rust-through on the floor pan under the seat near the drain plugs. The area's not much...maybe 6"x6" of rust-through on each side. The rest is surface rust that can be scraped/wire brushed off.

What's the best and most cost effective way to repair this? Without welding in a complete pan.

try some epoxy putty. It is 2 parts looks like modeling clay.

Thanks Lawrence. I'll look for some of that. Never heard of it though I've never done much body work.

Craig, if you are interested I saved a really nice rear pan under the back seat. shoot me a pic and i can cut off whatever amount you need for small patch work if you are interested.

Craig, if you are interested I saved a really nice rear pan under the back seat. shoot me a pic and i can cut off whatever amount you need for small patch work if you are interested.

Sounds great. I'll see what I can do about posting pics.