Do a compression test first. Fresh set of plugs unless they look great, regap the old ones if reusing.
Drain the fuel as discussed, put in Techron or some other high quality cleaner with a TopTier premium fuel.
Change the oil and filter, I'd suggest a 15W-40 diesel C rated dino version.
Run it and see how it reacts.

Good luck!!! And........waitin' for the pics, those are nice cars!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer