In a '63, the 1st coat (directly on the aluminum) is Zolatone - not vinyl like in a 70's model. Zolatone is (was) a speckled epoxy like paint that is very durable. It is still available today, although the forumations & colors are slightly different...they now have a water-based forumla too. Use the search tool to find out more.
Don't sand it off...unless you like a brushed aluminum textured finish...it will be very difficult to get the scratches out if you do. If you will be re-painting the interior, consider Zolatone as an option. One of the benefits is it is slightly textured when applied and will hide any imperfections, unlike normal solid color latex paint. If you want a shiny aluminum interior, keep at ti with the Aircraft Stripper, eventually after several coats, you will get down to the bare aluminum.
Good luck in whatever you decide to do!