Factory Caulk or Sealer, What was used where Options

[DennisV]

While addressing a couple rust areas, I ran into a hard white substance that was painted over body color. It appears to be squirted or brushed on pretty thick. It wasn't applied with much care. I was able to chip, wire brush, or sand it out. I'm curious:

1. Are these factory applications?
2. What's the modern equivalent?

Thanks.

This is surrounding the heater vent tubes in the engine compartment.



This is covering a half-circle cut-out in the driver floorboard just ahead of the pedals.


I'm guessing the same stuff was used in the rear trunk over the screws holding the muffler shield bracket.