I know this is an old thread but I stumbled across it and had to add my two cents.
I'm a model kit designer and builder ( designed the Seaview for Polar Lights/ Mobius). I my humble opinion, 1/72nd would be an ideal scale both for produceability (is that a word?) and profit margin. The kit would be quite affordable at around $150 and perfect for display at 30.31". If over 3500 Master Replicas were sold for $400+, I'm sure there are at least another 3500 of us who would shell out $150+ and that would almost pay for the tooling. I tried to talk Mobius into producing the kit for the 50th anniversary, had even started the exploded views and parts breakdown but no luck. I believe one of the concerns was the astronomical royalties Disney demands. Worse than Lucasfilms. But maybe if enough people chime into Mobius it might be worth their while. Who knows. Model companies DO listen.
Thank you for letting me vent.