Tune-ups are something one hears little about now. Electronic ignition of course has removed the need to change "points and plugs" regularly. Spark plugs seem to last forever now. Points? Huh!!! The older distributors didn't get the breaker arm and point assembly you dropped in. These had the whole works, the breaker arm and both points mounted on the assembly. You still had to set the point gap of course. The old distributors had the breaker arm with its point as one piece while the ground point was fitted with a screw with a jam nut on it. There was a bent up piece of sheet metal in the distributor that the ground point screwed into. You used a bitty little wrench to remove the old point and then fumbled and swore to get the new point started.
There were some power carts where the distributor was near the built-in cover around the unit, the part of the cover that didn't come off. This meant starting the screwed-in point blind and by feel. Of course you could remove the distributor, replace and set the points on the bench and then install and retime the distributor. But that was for weenies. Besides, you try and find the timing marks on an old engine that has been rebuilt, repainted and beaten up.
I know some mechs who swore by setting the point gap with the cellophane from their cigarette pack rather than using feeler gages. Seems strange now of course but since the engines started and ran it couldn't have been too far off.
Does anyone sandblast and regap spark plug points? That was a regular ritual too. Of course diesel has taken over many units and electric power has made huge inroads and will make even more. That eliminates the whole plugs and points thing.
One problem with pushback tugs is they don't run under heavy load for very long periods. They push back and disconnect and pull back in. The result is their exhausts never get hot enough to cook off some of the crud the engines emit. I know there was at least one tug that had a big stack fire, lots of flame and sparks from having to do a long tow after several years of never going more than 200 yards at a time.
An even more spectacular one was in the exhaust from a emergency generator built into an airline office building down in Miami. Three times a week the engine was started and run for a brief period to prove it was ready. Came the power failure and it kicked in just like the manual said it would. It smoothly picked up the load and grunted and settled down to carry its heavy load. It ran for some hours and the exhaust and muffler, loaded with residue from tri-weekly short runs, started cooking. And combusting. A rather spectacular stack fire forced a shutdown.