I believe I have discovered the artist of the Whaler Bar mural - it's most likely Bruce Church, who appears to be living still and has a web site. The picture above is from his web site and that clinched it for me - the clouds and something about the boats is very reminiscent of the Whaler Bar mural. For example:
I emailed him via his online contact form, so hopefully he will confirm his identity soon. I will certainly want to interview him for my Willie the Whaler article.
UPDATE: I just got an email from Bruce Church confirming that he painted the Whaler Bar mural. Progress!