It is pre 81 BLR but not exactly identical.
I received one but the magazine was 1 mm shorter than the original Browning.
When I was feeding the first cartridge in the chamber the magazine was moving forward and getting unlatch in back, the back of the magazine was moving down and the following cartridge was not loading anymore correctly.
I could see that the front of the magazine had been grinded some to shorten it during the fabrication. Certainly it didn't help
I had to send back.