It can be daunting to try to buy your first boat.
Here's where we can help.
We can offer advice, we can offer information. For example: your engine. It sounds like an M25 diesel, same as what I have in my boat. I put off buying a bigger boat for many years, 'cuz it was easier for me to lift the outboard off the C25 and bring it in for service! When we got our new boat in 1998, the PO told us it overheated. I did a LOT of research (pre-internet as we know it today days!!!) and figured I'd start with the HX. I took it off and found one of the inelt ports plugged up, cleaned it out and it worked just fine.
You're looking at older boats, but yet seem to miss the point that either YOU are going to have to learn to do the work (none of us was born a mechanic!) or pay someone else to do it. Most of us who have taken the latter course have regretted it, finding that what WE do, we do right the first time.
The engine room has been badly neglected. The Sherwood pump was dripping and incredibly rusted. The hose clamp on the line to the heat exchanger was broken and leaking. Water/exhaust mixing elbow shot. Fan belt, too. A few other items need work, too.
Though the engine seemed to run ok, the surveyor graded the engine room well below average. The engine tach was inop, and a Hobbs meter has been installed. It worked, with a total engine time adding up to about 600 hours. The surveyor felt that the engine looked like it had a lot more time on it than that sum would indicate. I agreed. It looks rough.
Engine ran OK - that's GREAT news.
Sherwood pump: it's crap, replace it with an Oberdorfer, as already said, maybe an hour of work for $260 for a new pump. Sources: that we can help you out with
www.depcopump.com
Our C34 website has a ton of information on these engines.
HX - take it off, replace the hoses. All of them.
Tach inop? Bet the PO didn't know any better. Probably a loose wire. Maybe his hour counter got stuck (they sometimes do) so he added another meter. That's good.
Dirty engine? Clean it! Geez...
We could go on, but if you expect a turnkey boat at that age, you're dreamin'. YOU have to make the choice, I got that part, but from what you've told us you found a good boat, with good "bones" that needs some work.
So what else is new?
Good luck.