poolnickv - I bought an O34 in "project" condition about 18 months ago. Happy to be sounding board if you PM me. I also replaced all the standing rigging. Your boat looks to be in nicer shape on yachtworld. I wouldn't worry too much about the blisters. Unless they are really big, they can just grind them out and fill with west epoxy and filler. You'll know a lot more after the haul out and survey.
Easy for me to be enthusiastic, since it's not my money.
But I agree that some old blistering is common, and (subject to closer inspection) is not a concern. When we had our boat hauled out for transport home, in 1994, the yard found an area on one side of the bottom, about 3' by 1', of noticeable blisters. They said their advice would be to grind out the gel coat in that area and apply a layer of new glass. They did so, and no blistering has returned. This was Mariner boatyard in Alameda.
Matter of fact the bottom was just recently repainted, the last week in the shop before launch, and other than some very small blisters here n there noticed after sanding almost all the old paint off, bottom is smooth. All perfect when painted.
Speaking of "project boats" ours was also
really a project when we bought it. All the main bent bits were repaired within the first year or two.
Any boat will turn into a "fixer upper" if beat up and ignored for several seasons, IMHO. The super/hyper important thing... is to buy a boat with excellent underlying
engineering and build quality that is worth your time and money to bring back. That's where a High End boat from Ericson is the best choice.
And no, this is not the only good brand - there is a 'short list' of other strong builders too.
Aside: I would love to visit Rob and his boat some day. Same guys built it, along with mine and Jay's boat (now in Chicago).