Thanks. I don't know why that picture looks so washed out. it's actually lighter and brighter in real life. Anyway, it's 34mm. i
hadn't known before i started to look that from 1937-1945, sports watches are generally 28mm to 32mm. Even for chronographs, I've seen Valjoux 22 at 32.5mm and Valjoux 90 (that's the triple date) at 34mm. For this watch, the movement is only 26.6mm so it would have been around 31.5 if not for the spacer.
You can find larger than 32mm but I would say that's only about 20% of the available stock. Also my preference was for stainless steel over chrome and gold-filled.
I know why people hesitate to buy 1940s vintage. It feels like you are asking for trouble. It will be tired they think with +/- 15 minutes a day and no parts to repair. It's true that the movement is old-school -- like when I turn the crown, I can feel some play where the crown rocks back against the click wheel. But it's actually pretty okay at -6 seconds / day and there are plenty of NOS parts available at Cousins.
This will be my one time-only watch -- i will head back into chronos soon.
Alpina died out in early 70s. It was resurrected by Frederic Constant around 2000+ and now is part of Citizen.