John Henwood's book on the Winchester Self Loaders doesn't show the magazines as being interchangeable on the common parts list.The .32WSL magazine has a second set of feed lips on it the others don't have as well as the magazine follower has a flat top,the .35,.351,and .401 follower has a trough milled into the follower to cradle the cartridge.Winchester catalogs show 5 and 10 shot magazines starting in late 1911.Best bet is to start cruising the auction sites for a correct magazine and even then the magazine may require fitting to your rifle.