It has to fit extremely tight, as in beating it on with a rubber mallet to work. If not, every time the bolt cycles the cover will jump and be off. These rifles were made by many manufacturers, with variations in design and are famous for loose tolerances. Zach - find out what kind of SKS he has. Russian, Romanian, Chinese norinco, etc. Value depends on who made it. Also, see if he has the original furniture, bayonet etc. you want that stuff, especially if the numbers match.