Rock Chick,
You probably know about this already, but the RAD have a jobs page (see link).
It may also be worth looking into universities and colleges- particularly at the moment, they're trying really hard to boost their inclusive capacities and may well be interested in a BSL interpreter; you may even be able to do a bit of job creation and could get yourself into an assessment position with regards to learning needs/classroom equipment which would help deaf students?
Lidy
RAD Jobs