Vasoline!
It is very odd to see huge cans of the stuff, especially on ship back in the day.
Anyway, the maintenance was to wipe the rubber with vasoline. So I took my parts that were not torn and washed them up with dawn and hot water. After that I loaded them up with vasoline, every nook and cranny. It wasn't that nice wipe down; I had a very good layer about two quarters thick covering the parts. I then wrapped them in Saran Wrap and placed them in a zipped lock bag. I forgot I had done that as I had moved onto the other parts of the car.
It has probably been about a year and while I was now looking to buy new parts I remembered what I did, although I had to find the bag. The bag turned up in a box I kept in the shed for the heat value. Apparently I also did it to other parts from different year cars. I found an early and late cowl drain tube, early and late trunk gas tank boot and a few other rubber parts. About an hour ago I took them out of the bag and wiped them off. They sure are pretty and very pliable.
It is a thought if you are going to be working on your project a while. Now I can spend the saved money on other parts I need.
So what did they put on our cars 