Thanks for everybody's help. I plan to make a neo skirt someday, but since I already bought a new skirt, which doesn't fit, I'm trying to resolve through the outfitter. I talked to Snapdragon again and they offered to make a custom skirt if I would send them a template of my coaming. Since this will take another 2 weeks or so and there is no guarantee that the custom skirt will fit, and the water's gonna turn to ice soon, I decided to try to find one that fits first.

Well I didn't have to look much; Mark Bodian at Outdoor Sports in Wilton CT just looked at my boat and immediately knew what skirt would fit. And he gave me a rental one for a while to check it out. The logo on the skirt top says Boreal Design with pictures of Pinochio whales (nar, ya know), but the inside tag says "Brooks Wetsuits - Large Keyhole", and it fits perfect.

About the location of the tube with respect to the seat. I did some tests on my Tern 14 to check for and aft trim an found I was always down by the stern. This made sense since I didn't install the forward hatch and bulkhead and I was not spreading the payload. Because I have inflatable positive flotation in the bow it is hard to get enough weight in front to trim the boat. So I moved the seat forward 3 to 4 inches and the boat now settles nicely into trim and handles a lot better. Before I did this my nylon skirt didn't fit right, it was too tight in front. But now its fine, and the new neoprene skirt tube is also perfectly aligned with the seat. (The reason I say 3 to 4 inches is because I added an air bladder behind the minicell back support.)