Tim,
I got my stromberg's from a guy near Chicago. His name is Ed Graham. I met him through a couple of inliner guys that live near me. I guess he collects them and rebuilds them. A bit pricey, but I really wanted them. If I was building another engine, I would get some zenith carbs from Vintage Auto Parts. Even Ed says they flow better than the strombergs.
The big thing about the strombergs is they don't leak.
Bill