Finland adopted the AK in 1962, as the m/62 – a milled receiver pattern. By the late 1960s the Valmet factory was experimenting with stamped receiver design to reduce costs. The first stamped Valmet rifle was the m/71, which used forward-mounted open sights like a regular AK instead of rear-mounted aperture sights. The m/71 was rejected by the military, and so Valmet put the stamped receiver into its m/62 instead. This was approved for military used a the m/62-76 in 1976 and production began in 1977.
Valmet had also begun exploring options for export sales of rights in the 1960s, to balance out demand with potentially unpredictable military sales. They received permission to ell an export model of the m/62 in 1967, and from that point on they offered all their designs on the export market (including one like the m/71 that were not adopted by the Finnish military). The m/62-76 was no different, offered as the M76 commercially.
There were a bunch of options on the export M76, including both semiauto and full auto models (this one being a semiauto example) and at least four different buttstocks (wood, plastic, fixed tube, and folding tube). They were made in both 5.56mm and 7.62x39mm, with the majority of US sales being in 5.56 because 7.62mm ammunition was simply not available in the US at the time.
Production for the military ended in 1982, with the determination that the stamped receivers were less durable than milled, very difficult to repair when damaged, and they did not actually cost less for the military. Valmet scaled back its export production at the same time, choosing to focus on other rifle models instead.