What everyone here said about B&Ms. Likely to find it there.
Start with B&Ms near you that you can travel to and pick up in person. If you call a shop and they see a far away area code on caller ID, they are likely going to tell you they are out, even if they're not. Something like, "Hey I'm coming by later to get some pipe tobacco, just wanted to check first to see if you had any Penzance/Stonehaven/etc." Even then they might say they don't have any. They will want to save it for people that are actually in the store.