I have for sale a 3.5" BSA pattern steel underslung handlebar extension. This is minus its clamp and expander bolt. Chromium plate is excellent minute loss on front of stem. There is 2" of very good plating on the upright section. £10.00 plus postage. This is a 1950's track extension but would not look out of place on any 40's to 60's machine. Another shed find.
Best wishes and be lucky. Michael Butler Huntingdon UK.