This means Royal Ordance Factory Fazakerly, Factory Through Repair, 1949. The latter will have an engraving on the flat side of the receiver which will read something like (taking one of my rifles as an example), F(FTR)49. If it has a lateral screw through the back of the forend, it is either a post war production Mk.2, or an earlier mark that has been rebuilt. Apart from the markings as stated above, you should take note of the woodwork.
