Open or Don't open vintage parts bag.

[TREAD]

I'm looking for some advice. I have a LJN Thundercat's Thunder Tank in its box, I have had it for about 35 years now. The tank treads and instructions are still sealed, and I have taken the bag out to check the treads once a year to see if they are still pliable and they are. Here is the question should I leave them be or open the bag and condition the treads with an oil. I am worried about the rubber deterioration.

 

[Mr. Awesome]

If after 35 years and the tires are still fine, I'd say leave it sealed. Seems to be offering them adequate protection as is. That's if leaving it sealed is preferable, that is.