I looked on the SIGAda web page and it had eleven listings (www.jobserve.com
has some 200+ Ada jobs in the UK). They were:
4 location unspecified
3 Huntsville
2 Australia
1 Grand Rapids
1 Alexandria
I've been doing contracting and consulting in C, Java, etc. for almost 10 years
because the Ada market in Northern VA doesn't appear large enough to support
folks with the kind of experience that you describe (translation - pay them
competitively).
-- Karl --