Were they using the nylon return line as late as 88? Here are some things I've learned about the sender and pump in the tank.
In The Tank
--
Art Benstein near Baltimore

A man was driving down a muddy road when his car unexpectedly became stuck in the puddle of mud. Despite his best efforts, he was unable to get his car out of the hole.

He abruptly noticed a villager riding his bullock cart near him.

He asked him to extricate his automobile from the mud as soon as the bullock cart arrived. The farmer used his bullocks to pull the car after they agreed to a price of Rs 1000 for the service.

He gave him the money after giving him a huge sigh of relief.

“There must be many cars that would get stuck in the muck like this,” he inquired of the local man.

The villager responded, “True sir, “You are the sixth guy since morning whose car got trapped in this mud.”

Man: “Oh my God! so you pull all of them off. “

Villager: “Yes, sir.”

Man: “This service keeps you busy for a full day pulling the cars from the mud, having no time to do your own work.”

Villager: “Very true, Sir. I have to do all my work at night only. “

Man: “Oh, I see! By the way, what is the main work that you do during the night? “

Villager: “I just ensure that this mud is never dry.”

A good part of the government’s job is to ensure that the mud is never dry. -- famous paraphrased by Abhishek