You are correct, Carl Gustav is to Sweden what Springfield is to the U.S. However, starting the in late 1960s, Husqvarna made/sold sporters built on the 1900 action under the FFV, Carl Gustav, and Husqvarna brands, as well as the Tradewinds and S&W brands for the U.S. market.
I have a FFV/Carl Gustav in 30-06, #5093xx, that is built on a 1900 action.
There has been some discussion on this topic on the Gun Boards Swedish section and Stuart Otteson wrote about it in one of his bolt action books, I think Volume 2.
