As a playwright offered a slot for my play in January 2010 at a known fringe theatre I aim to find an experienced producer, director and 2 actors (NB 1 male age 50s and 1 female age 40s, both experienced). I am looking for prospective producers (also possibly actor/producers who fit the casting bracket) who may know a director 'mate' they are happy to work with. Know anyone? Thank you.

hey you should take a look at fringe companies working and what hey are about, then contact the directors/ producers directly.
good place to start is by goin on the listings and such like.

If you look at the ages my play features, players in the forties and fifties age groups tend not to appear in the places you mention.