Re: Buying a 30-40 year old boat - your opinions
I have a '74 Cal 29 and have done an extensive rebuild/overhaul. Going into details is a topic of its own. Some general observations:
Get a good surveyor. There's wide variance. Often insurance companies and boat yards know who will make a though inspection. A diesel survey can be an expertise of its own.
Boats reach a "fully depreciated" price normally well before, probably at about the 10 year point. At that point depreciation flattens out so you don't necessarily get more value per dollar going much past that. Some specific classics may even improve after a point
I recommend avoiding boats that have big ticket needs. The need to repower, hull blisters, deck water intrusion, need to replace rigging/sails. Get a boat where that's already been done.
The best value in an older boat is where the previous owner's put in a lot of TLC. You never get out of a boat any near what you put in. That's not the point in doing it. Some older boats have been greatly improved by owners over the production boat and that can be a great value to you if the improvements match features that you want. this is particularly true of performance designs. They are great to sail but need considerable improvements for sustained cruising.
ABYC boat standards have changed. For example I ended up rewiring much of my boat because the original work was just to a lower standard and that showed.
If you like carpentry, a stick built interior is easier to work with than a molded interior
Don't count on electronics having much value after about 7 years. You'll probably find yourself making replacements.
Check the web for class information. Boats invariably have an problem the develops with age. It can be a costly one if you have to fix it. On the Cal 29 its the beam that absorbs mast compression. Anyway you can check for it and see if its been corrected.