I have found two neat surplus pouches that will hold Tib mags.
First, and best is the 1950's era M1 Carbine 30rd mag pouch. There are many "flavors" out there, but the best is this particular pouch designed to hold two 30rd mags and a pair of stripper clips. The flap covers the pouch, which contains two interior dividers that seperates the two mags from each other.
Second is any mag pouch designed for the twenty rd. Thompson mags. The typical mag pouch like this has five compartments that are exactly the right size for Tib mags.