A Very British Civil War is a period based on an alternate history of Britain in the 1930's. Plenty of enthusiasts out there, and having read up on some of the backstory and details of the period a lot of the alternate path does have some credibility.
The main inspiration for this period is the 1995 film starring Ian McKellen as Richard III.
If you've not seen it, this is a great take on the classic Shakespeare play and well worth seeing.
Richard III - IMDB
AVBCW will be making an appearance at Wappenshaw, with a game presented by GDWS - Glasgow and District Wargames Society. Glasgow Green 1938 - VBCW
As an example of the genre, here are a few pics from the game put on by Dumfries last year