I am not sure about some of this, so please contact me if I am wrong about anything, or if you can add more information.
The original manufacturer was Valmet, the state-owned metal works company in Finland (VALtio = state, METall = metal) The original name was perhaps the State Metal Works - Valtion Metallitehdas. Valmet was a large company with different divisions for shipyards, papermill machinery, cars (SAABs was assembled in Finland by the SAAB-Valmet works) and tractor manufacturing, as well as large marine engines and measuring instruments, but also guns and cannons etc. They built Scandia diesel engines (under licence) from 1947, and Vire inboard marine engines from 1949. Among the earlier models were the 6HP Vire BVR, and the closely-related BVK and BV models. Valmet may have manufactured the Vire 7 from 1969 onwards, or production may not have started until 1973. They probably manufactured the bigger Vire 12, which shares many mechanical parts with the Vire 7, from about the same time.
At one time Vire engines were manufactured in Jyväskylä. It would appear that Valmet are no longer in the business of manufacturing engines, although their name is still associated with agricultural tractors. In 1975 their address was: -
Valmet manufactured both big diesel and small petrol marine engines. In recent years manufacture of their diesel engines has been taken over by Sisu Diesel, also based in Finland.
According to Sisu Diesel, Valmet also manufactured almost 15,000 of the smaller Vire engines. Manufacture of these engines was then taken over (in 1984 ?) by Masnedø Marinecenter A/S in Denmark. Their contact details are:
Masnedø also manufactured the Vire 12, but later discontinued making them. Alas, in April 2002 Masnedø stopped manufacturing the Vire 7 too. By April 2003 their inventory of new Vire 7 engines was sold out, altough they still had an extensive list of Vire spare parts.