From what Steppe stated, it sounds like Pacific Trawler used (at least on some boats) Tides Marine seals on the rudder. That is what was used on my Nordic Tug. I removed the rudder a couple of years ago so I could remove the prop shaft to replace the dripless, "tune the prop", replace Cutlass bearings, and replace the rudder seal. All preventative maintenance. I have a rudder angle indicator also, and it was not an issue. The rudder came out and went back in with ease, with that part of the job taking the mechanic about 1 hour (or less). If all you are doing is replacing the rudder seal, the rudder does not need to be removed. My mechanic did not think (at first) that the rudder could be removed as easily as it was. He at first wanted to drill a hole in the rudder to allow the shaft out. I had an article from another Tug owner who described the process (and seal replacement) in good detail. Send me a PM with your email address if you would like a copy of that article. It does not all apply to you, but there may be good info (even for a mechanic who may not be totally familiar with these systems)?
Based on the post Peter referenced, your rudder system is a bit different than mine. On mine, if only doing the seal, it could be done with the rudder in place (but on the hard to ensure no leaks)