A lot of Volvos in A25s were seawater cooled. A likely scenario is that it is the same one as many (perhaps most) of those Volvos have choked on salt or got eaten away. The argument against that is that the YW A25 looks like it has the original cockpit coaming.
Anyway it looks like the guy did a good job w it unlike some boats that get modified that much. A lot of people will think they need more than 20hp though. If I saw the detail work I may be able to be even more positive about the boat. But it's hard to make a boat that is just about the best boat in the world even better.
My 1st wife's brother bought an A25 w an old Volvo that had been hacked up and converted into a fish boat. He put paravane stabilizers on it. The boat was a junker when he bought it but he's the handiest handyman I've ever known and a hard worker too and the boat turned out really good. He restored a Model A and one of those old diesel Land Rovers too. So a modified or remanufactured boat can turn out very good given the right owner. Even better than new at times.
North Western Washington State USA