Not sure if this is the same thing you are talking about but on my 65 C10 the radiator has several kind of U shaped rubbers that the radiator sets in. Everywhere there would be metal to metal contact, there is a rubber.
The radiator is made of brass, and aluminum....ie SOFT metals, and the brakets that hold it are STEEL, and very hard.
If the two contacted the vibration would wear holes in the radiator in no time.
The rubbers are not all that soft....not like window or door weather stripping.
As for the staples......my rubbers have little **** that fit in a hole in the braket. That keeps them in place.
I would think.....regular weather strip adheisive would take the place of the staples, and hold the rubber.
This is ALL just a guess though.