Does anyone own any yards or bolts of uniform fabric? I like to sew, and I've sometimes found collectors occasionally have rolls of deadstock camo fabric.
I'd check Alibaba, you can get tons there. Also the Facebook group Camouflage Addicts as there's a lot of members there making custom items as well as selling or inquiring about bolts.
Depending on what type of cloth and camo you're looking for, there's quite a bit that shows up on eBay. Just stumbled upon some very nice experimental Bulgarian DPM (white color) is available. The real cloth isn't cheap, but it is certainly out there. I have a bunch I bought to cover things with.
I would steer away from Alibaba simply because of the cost. The vendors are supposed to be vetted, so I don't think they are any more of a problem than you would find anywhere else.
I do not know of this shop, and it is EXPENSIVE, but here's Swedish desert and temperate Splinter: