Marvel Mystery Oil to the Rescue!
When I was a lad, we resurrected and unbent a wrecked MG and the next year, a wrecked Jag. Upon the advice of Charlie O'Dell, Master Mechanic at the Hudson dealer, we squirted Marvel Mystery Oil in each cylinder, after sticking the fuel line in a bucket of fresh "Ethyl" gasoline.
The MG started right up, but the Jag needed a squirt of ether in the carb.
I do not know what is mysterious or marvelous about this stuff, but it is still in the stores and comes in a red and black can.
The Stdebaker mechanic said we could also use Bardahl or even Wynn's Friction-Proofer.
Semibodacious Transmogrifications a Specialty
1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)
"Time flies like and arrow, yet fruit flies like a banana"