Alright, people. I just now spoke to the shop on the phone, and Inverallan has said that the remaining 3As should be sent (from Inverallan to the shop) this coming Tuesday. I'll hear from the shop when they arrive for sure.
Apparently the current director of Inverallan is stepping down next month, and from what I've heard it's possible that the company might start winding down production for good at that point. I'm hoping this doesn't actually happen, but if it does, I can imagine that there will be several small groups or individuals that would start their own ventures. After all, the demand is certainly there! The shop owner did tell me about one UK-based heritage knitting company that he's helping to relaunch this coming year. So, I think there will be plenty of nice options regardless.