Thanks for the welcome Dave; I look forward to learning about Douglas's and eventually contributing. I have a gut-feel that I will be restoring the bike without original/reproduction parts, rather, using parts the “look” the period, as I am state-side (no sources). I am an engineer, and as a result, I have contacts capable of fabricating certain parts. I contacted a tubing fabricator, and as luck would have it, he is producing a “run” of mild-steel tubing, 1.375 inch in diameter, with a 180 degree bend about a 6 inch radius (through the center of the pipe). This appears to be the correct dimension for the Douglas. It is my intension (unless I find reason not to) to run a straight pipe, all the way out the back, without a muffler. I will have the pipes chromed. My biggest concern is finding a speedometer with the correct ratio for the existing output on the rear wheel. Do you know of a “drop-in” replacement form another bike?
Take care