I'd focus on your portfolio and any experiences you can point to that show good working practices. Do you have an old prompt book, or paperwork you can show a potential employer? Can you point to a show at a theatre you worked that was well-received?
Don't just focus on past directors/employers for references. Are there actors who appreciated your care? Maybe designers who you worked well with? Are there personal character references from your recent work (outside the theatre) you can point to?
So far as building references and getting your toes wet, a lot of theatres will accept volunteers to begin with. It's not ideal, of course, but it's a way to get your foot in the door. Maybe offer to come in and help with load-in, or ask if there's a volunteer ushering group you can join. Industry nights at shows are also great mixing opportunities.