new owner of a 65 Country Sedan with the 352. Car is in Wonderfull condition, Except fuel tank is rust on rust. good enough to boil out? Does anybody know if Ford shared same tank with other?

I would buy a new tank from a classic car parts maker/catalog, plenty of them out there. Don't waste your time trying to hunt down an old tank from a 60's era car. This link is just one of many companies out there that make replacement tanks: http://www.dearbornclassics.com/fuel-systems/gas-tanks/gas-tanks.html

While brand new replacements are plentiful for sedans, coupes, hardtops and convertibles, and even earlier and later Ford wagons, not so for the '65 thru '70 models. I have a pair of '68 Country Sedans, both with rotten tanks, and what I've found is that nobody makes replacements for these. The local radiator shop sez they're both too far gone for rehab. Is my last resort to hire a welder/fuel cell builder to custom-manufacture these for me?

Obviously a custom tank is the last resort. As an alternative you could install a standard fuel cell in the trunk.

These are station wagons we're discussing. There is no trunk.

In your post you said a pair of '68 Country Sedans. You can still mount a fuel cell in the back of a waggon. Not the best solution but it will get you back on the road. Perhaps there is a type sold that can be mounted underneath the car. Check out Summit Racing for fuel cells and generic gas tanks.

I also found a tank that fits in a spare tire well. Not sure where your spare mounts but you can check it out.