Well, if it is the old ALICE pouch, about 3"x3"x7"... sorry, about 7.5x7.5x17.5cm. So it would be tight, you might get enough wiggle room but I'd be surprised. Just barely too small.

As I recall, you guys had a pouch that held three FAL magazines as part of your LBE. If you could find one of those in a surplus store, it should work with the tin in question. Baring that, if you were still thinking MilSurp, look for a clone of our newer canteen cover.