There seems to be a growing problem with engines of late. I see various things interacting to cause at least a good part of this. First, while mechanics today are indeed well-trained and experienced, the engines of today are significantly different in construction and metallurgy for parts than those of the 1950's and earlier. Fixing older engines the way you fix today's motors results in "skipping" a number of checks and steps that are critical to a successful major overhaul or rebuilding of the motor. As a result, engines may be rebuilt without such things as proper flushing of oil and water passages in the block (you need to do it several times to get all the crud out; failure to do so just shifts the junk to places where it jams and blocks passages causing overheating or lubrication issues), blocks and heads are not checked properly for cracks and fractures (ask some of today's mechanics about Magnaflux testing before re-assembly of a motor for a Hudson or a Kaiser), and resolving damage caused by today's gasoline (things like seal deterioration, valve seat recession on the block and other deterioration from the alcohol-based fuels)? If a rebuilder proudly says (or you supply the rebuilder) with the original NOS rubber or cork gaskets and seals, you may as well have everything done all over again because those things are no good under todays fuels and operating conditions.
There are plenty of good sources of parts and mechanical expertise. Members of the KFOCI know this. Not making use of resources (especially if you've never done a pre-1959 vintage car before) is in my opinion something that does not have to happen. If you are not aware of the factory's "how to" and diagnostics guides in factory service information you can be heading for a lot of trouble. It seems safe to say that you may be able to avoid a lot of costly headaches due to what your local "expert" mechanic does not know about the old stuff because how much has changed under the hood of a car since 1965.
If you are a member of the KFOCI you can run free ads in the club's monthly Newsletter (which just one another award for excellence in publication) looking for parts, assistance as well as check out the items for sale by others including regular vendors. Being a member of the Forum or Kaiser-Frazer fan club does NOT make you a member of the KFOCI. For information on joining check out the KFOCI's website.