Prohibition

So, I've been toying with the idea of setting a Planescape game in a 1920s - 30s themed setting, complete with organized crime, speak easies, and attempted Prohibition by the Govnors and Hardheads, Bootlegging, Flappers, Jazz, etc.  And was curious if anyone could offer me some good ideas I hadn't thought of.

I'm going to have the setting fairly humancentric, with most non-humans in Sigil being either of the very near human variety (most of the pc races) and have the more bizarre creatures either taking human form or forced into a human-esque mold by the power of the city. (Ogres would look like large, brutish humans, kobalds would appear to be dirty street urchins, etc.)

There would still be magic and plane travel, with a large train depot in the Lower Ward leading to most of the outer planes or their gate towns, while I envision the Ethereal as a vast way station packed with travelers to the prime and the demiplanes.

Cars, radio, telephones and the new moving picture would be fairly common sights in the City of Doors - which I intend to play with a gritty, Noirish vibe.

Since I know we have some infinately creative people here, I am hoping to get some input on ways to make this work as effectively as possible.  Any and all ideas are welcome. (aside from "ditch the noir" or something equally unconstructive)

Thanks