Some good British bands that played New
Orleans style jazz are those of Alex Welsh
and Ken Colyer from around 1950 - 1970.
A good source of this kind of music is the CDs
issued by Lake Records of Workington, Cumbria.
Their address is Lake Records, PO Box 40,
Workington, Cumbria, CA14 3GJ.
Website: www.fellside.com
Ask them your question, they are very helpful, and
you can buy by post.
For the real stuff you have to go for the music
of King Oliver, or the Louis Armstrong Hot Fives and
Hot Sevens of the 1920s. But you won't find a double
bass in these. If I were you, I'd stick with Welsh or
Colyer.