Some Wednesday’s back in the day there were multiple 50s a 70 and once in a while Merlin. One Wednesday I recall there was a powerful northerly which means flat water by the beach and we watched Merlin beam reach on plane from the pier past the boardwalk to the harbor mouth. Maybe 30 seconds. Like a cartoon. Then I got to do it on solings. Faster than the swells. Did it on an Olson 40 too. Ride over two or three swells before a lull drops you off the step. Nothing like it. Feels like you have harnessed a special power.
My Olson 40 is about the same age (1983), and is entirely balsa core. There is nothing whatsoever bad about the balsa in my boat. My boat was ridden hard and put away wet for over 4 decades before I got her.
No doubt your Olson is in great shape, as are a lot of balsa cored boats. But I would rank Olson as one of the better builders of ULDBs in that era. And yet I owned an Olson 30 several years ago that had completely rotted out and ended up in a dumpster. The reality is nine out of ten times when reading about someone having to do a recore job balsa is involved. So if I was looking at two similar boats that had obviously been neglected for some time and had a choice between balsa core and foam core the latter would get my vote every time. If I was having a new boat built, was using epoxy or vinylester resin, and utilizing infusion or at least a vacumn bag balsa would be my choice for all the reasons you mention. It really is the superior product (for me, at least) but has to be done right. I should mention the NW is not like CA- it's really wet (rain) where that boat is moored. Nearby Shelton gets 68" of rain a year. If that deck, etc. could leak anywhere- it probably did. Hell, sometimes the moss/fungus grows under the glass- I've seen it.
say it ain't so!