That style of brake is called a "Roller Cam." They were a Charlie Cunningham invention; the originals were sold as a WTB product. The Suntour Roller Cams were made under license, and used the same design. Shimano AX brakes were a road part of similar design but totally different application. They clear skinny tires only, and were more designed to compete with Campy's ultra-aero Delta brakes. The ones worth the most money are original WTBs in good shape. All of the MTB-spec roller cam brakes, as far as I know, are designed to be run on u-brake posts, like a bmx bike might have. The Norco in the OP was running a bolt-on u-brake boss on the fork, and someone mounted the roller cam brakes up to that.
Those brakes have a bit of a cult following; some 80s mtbs ran these front and rear, whereas others had a high-pro canti up front and a roller cam (or just a U-brake) out back. I personally like these brakes, but they're not very practical on a bike that sees a ton of mileage.