I found these girders and late 30's/early 1940's race tires at a car swap meet along with lots of other very early British and American motorcycle parts. Most parts were 1940's and earlier but nothing was newer than the late 50's. It was a local collector that passed away and his grandson was at the swap meet liquidating for very reasonable prices. Keep that in mind fellow hoarders! I'm waiting to check out a few early Norton singles (International and an ES-2) from the same collection as well as an extensive collection of Whitworth tools. Fingers crossed.