My current singlespeed is built around a modern frame that has vertical rear wheel mounting slots, which means I have to use an ugly durrelier hanger as a chain tensioner. The tensioning of the chain is only the tip of the discontent, I've never liked my current frame even although theoretically there's just nothing wrong with it.
After a few false starts I finally found a nicer frame for my bike, a lovely old Dave Lloyd frame (with horizontal rear wheel mounts). I'm not sure exactly what what the tubing is made of, but it's fluted in all the right places and butted where you'd want to see butting. A better man than I has guessed that this frame is probably made of Reynolds 531.
Today I started the joyus work of preparing the frame to take the kit from my current bike, and as an aide-memoir as much as anything else I've decided to log the work I'm doing for this conversion.