I would try to give him a call in the earlier part of the day, before he gets into his work routine, or send him an e-mail requesting him to call you...He's usually pretty good about getting back to you, unless something critical is going on at his end..
I was lucky and ordered my custom upper in the Spring of '08, before the 'rush' started, and had mine back in about two months..At that time, I sent a 50% deposit to start (that way his material is generally paid) and the balance when he was ready to ship, but he may have a set schedule by now...