Like all 30+ year old boats, history makes a big difference on the current condition. Specifically for the 4588 beware of water intrusion on the fly bridge deck from unsealed penetrations, same with the radar arch and the front deck around the anchor locker. Hinos have proved to be a very rugged diesel but some parts are getting harder to find but there are distributors in the PNW. These like the 4788 have poor access to the engine room but a cutting in a center hatch (common modification ) alleviates that problem.
These boats are a terrific design with more usable living space then some boats that 7 to 10 feet larger.
If you can find one that has spent it's life in covered moorage so much the better.
BOC is a great resource to get any additional questions answered but like most boating websites you tend to see mostly issues and complaints posted.