Impurge, due to the necessity of such a part to be flexible, I haven't done much more than consider a belt and holster combo like you suggested. I do have the holsters and ammo pouches and feel that crafting the rest of the belt assembly using paper or styrene strips would be possible. Another option would be to take a kama with the belt and holsters from a clone commander figure, and cut the kama away from the belt and holsters to leave a piece alot like the one that came with the Geligrub trooper.
I have done this twice before on a couple of clones in my custom figure thread with some success.
The ammo pouches sound interesting. Send me a PM about it.
Figured something like that would be pretty complicated, and probably cheaper just to buy them lose compared to the cost of trying to mold something like that with trial and error and all. But figured I'd ask anyway. Would you happen to know off hand if the holsters are pretty much the same between Gelagrub troop and Capt Rex. Might just have to buy a couple of those from you.
Regarding pouches I'll see if I can snap a couple pics and send them your way in next couple days, have to dig them out of parts bin.
Also have a couple of VTSC Hoth Han hats that I'd Xacto'd the "scarf" of. 1 I'd left the goggles on, the other I Xacto'd them off too. Minus scarfs they make for good rebel hat, for officers and what not. Couldn't afford buying more Han's for just the hats, and the General McGuire that came with same hat kinda sucks and wouldn't be worth army bldg for hat either. So interested let me know. Haven't gotten around to painting them either. Will snap some pics too when I get the pouches too.