I too did the same research and got the same result, TWO YEARS AGO. To my knowledge Glen Affric only weaves for Scotweb as I could find no reference anywhere to any other weaving of tartan for anybody else.

Just for the record, unless someone holds the exclusive rights to a tartan design, it can be woven by any of several weavers as a special weave, but most who need just enough for a classic kilt will get it done by DC Dalgleish, as they seem to have the best price for custom weave short lengths, and reasonable turnaround time as well. Works best if it is the kiltmaker who contacts them with your request, so if you have chosen a kiltmaker ask them to contact Dalgleish about the custom weave Maxwell Hunting costs and timeframe and they can get you the info and a confirmed quote. Just about any of the kiltmakers we all know around the forum can do this for you, and probably cheaper than trying to order the tartan yourself.

jeff