It's real hard to tell from the pictures, but I see the spots you are talking about, and it does look like a big blister. But it might just be a paint blister, not a structural blister.
The other yellow flag I see is that the pictures are not all the same vintage, and probably very different vintage. Most of the differences are in the flybridge pictures where the upholstery changes from beige to blue, and the console changed from FRP to a wood overlay. So in at least some of the pictures you are seeing the boat when it was much newer, or perhaps even a sister ship or stock photos of the model.
Have you seen the boat in person, or is that what you are trying to decide to do?
Re blisters, I have seen surveyors use a moisture meter on hulls, but I don't know if it would show blisters, or if it only shows water logged areas. But I'm wondering if you could use one from the inside of the boat to get a sense of the hull condition by measure from inside bilges, etc. to get a sense of hull condition before spending $$ on a haul out.
To me one of the challenges with a boat in this value range is that you have very little room for repairs before you find yourself with a lot more money in the boat than it's worth. So it needs to be pretty perfect, or the price needs to change quite a bit. For example, I would image that stripping the bottom paint, doing some blister repair, barrier coat, and repaint could easily cost $50k-$100k. But I have never done it, so might be way off. It just seems like it would be really easy to end up with 25% to 50% more into the boat right from the start.
