I love all things art deco (hence joining the site) and would LOVE to know if there were any conventions/formal events that i could use as an excuse to dress up for!
Such an interesting website, i look forward to your replies! :)
In the US, it's hard to come into a major city without accidentally tripping over a speakeasy, but I'm not sure how popular they are in the UK yet. Your best bet is to search for swing dance and jitterbug groups in your area. Those are usually local, knowledgeable of the time period, and always friendly towards new members.
As for dedicated "dieselpunk" groups, I'm sure if you said "meet me at X on Saturday night to hang out and chat," you'll get a group forming within the first few weeks. The key is to make it happen on a regular basis and to keep it going. Look at the Steamrats in Seattle for example. It was just a small group of local steampunks that got together at a coffeehouse every Friday night to play games. Now, it's a dedicated community that takes side-trips to fun locations in the city along with their weekly event.