If you'd like to get a couple people together in order to have a few made, I could check with Select Plastics in Norwalk for pricing. I don't think they'd do drawings/specs though and I don't have the skills to do that myself. Actually, to even get a rough price, they're going to need a decent picture and a guess at the overall size.
Whereabouts are you in LI? If on the North Side, you may even want to just take a trip across the sound to Norwalk. Select Plastics is across the street from the public dock/ramp. I also work in NYC, if you do as well, maybe we could just meet up there.
http://www.selectplastics.com/