If your new aquisition was never on vegatable oil. There are many possible reasons for what is occuring. With the use of the archives or other help from this site it should be a walk in the park hopefully. Car looks very nice by the way.

Did the mechanic tell you how he verified there was fuel in the pump? The lift pump having output is no certainty there actually is. Now collecting overflow from the return line off the injection pump would while cranking. Always remember these older six cylinder engines in line type injection pumps are pretty reliable in general. Of course failure modes are not unknown. just not common.