OP, pm me and I'll send you my broker's contact info. I was in the same boat, almost (sorry, couldn't resist): trying to find coverage for a home-built wood boat that had been under the PO's homeowner's policy. I found out like you did that companies don't want to cover older boats without a survey. I was prepping to spring for a survey on a 25'er I was getting for about what the survey would've cost me. In the end I got an agreed-value policy and liability based on my experience crewing (no certs) and detailed pics that showed she was shipshape.
But either way I could believe a good broker could get you liability coverage with a hull/engine survey.