Brandon is really good about getting back to emails. I've had two orders processed so far this year, and waiting on my third. I think 3-4 weeks is typical if not listed as backordered, but I also know that he has an atypical number of orders to process right now. When in doubt, just shoot him an email.
I can see where it would be helpful to set expectations of delivery time up front during ordering. I think for example just a quick note on the website saying that some orders may take longer due to current workload would have helped out a lot.
All I can say beyond that, is that his stuff is well worth the wait.