I bought this firearm with a postal bid to one of the Classic Arms auctions. The description said that it was a B Super, but after I had licenced it and took possession I found that it is in fact a BS -- in other words, a standard toggle-link Model B with an added magazine safety.
It looks like it's been through a war, and in all honesty this is rather likely.
It shoots well though. I shot this target with 8 x mixed headstamp NATO FMJ, 8 x FMJ reloads and 3 x 8 x cast lead TC reloads.