I believe that Firearms International Company was simply an importer and distributor of firearms, not a manufacturer. I believe it went under the name FIC. Import companies come and go, and I doubt you will find anything interesting about them. They simply buy the firearms from Europe (or elsewhere), stamp their names on the barrel as importer, and sell them wholesale to chain stores and other retailers.
The only important thing here is that your rifle was made by FN (Fabrique Nationale) in Belgium, which means that the action at least was top of the line. The particular model name you give was probably inexpensive model, because of a low grade stock, an inexpensive barrel, and typically no floorplate. Still, these rifles can be made to shoot very well.
FN also sold inexpensive rifles in very large numbers in the 1960s to both Sears, to be sold under the name of J.C. Higgens, and I think Montgomery Wards, to be sold under the name of Western Field.
Hope this helps.
Big Paulie