there are 10 round ak mags out there, I have seen them, but just never though to have a use for them. since it is a 10 round mag, and not evil, it should be okay, if you were to get a Weiger type, and screw a sheet metal screw, down into the lower 'lip' thingy, that clicks into the top of the magwell, then put in some red loctite around it. that will act as your bullet guide.
there is an old timer, that sells all kinds of parts, at / around Houston gushows, that has the
10 round ak mags. Someone up there is bound to have some...