I had the exact same issue and tried to get by "for a few more seasons." Tried some quick fixes that never worked. The engine ended up shifting a few degrees to the side and my prop-shaft wore a hole through the side of my shaft log. The boat sank (luckily we made it close to shore and it was only in a couple feet of water!)
I had high hopes for the CPES/rot-doctor solutions and even spent quite a chunk of change on them. Unfortunately, my research showed that they wouldn't accomplish anything unless you could dry the wood out. I'm not sure how this would ever be possible unless you had a drive-in wood kiln to park the boat in for a few years.
I don't mean to crap all over your thread -- I think your solution of pointing out the problem to the next prospective owner is fair and I think your price is reasonable. It's a beautiful boat and is going to make the right person very happy after they undertake the proper repairs. Good luck!!
Former owner of a 1987 Supra Saltare. Current owner of a Malibu 23LSV.