As I have had a mid 1940's frame sitting around unused for several years, I thought I would start on a stretched bike. My plan is to simply upscale a stock bike, by extending the down tubes 4", and letting the other tubes find there own length. What I did is cut the bike into 3 sections, and reassembled it with thick wall tube that I turned down on a lathe to make inserts. This will enable me to figure out the other lengths of the stretch, and cut extension sections to fit between the cuts.
On with the pictures. Here is the junk I started with.