As to the Golden Grain, it could be approximately dated by the tax stamps.
As to dating the Velvet, the “humidor” snap top lid was introduced in the late 1940s and the amount of tobacco reduced from 2 to 1 1/2 ounces likely in the later part of the 1960s. They were trying to keep a pocket tin at 15 cents as long as they could.
Pipe tobacco can mold, but I’m starting to think it cannot really spoil, or get skunky, so long as the flavorings used are not biodegradable.
I hope your heirs are able to make a decent living without selling your collectible tobaccos.
The Golden Grain can be rehydrated by simply placing the sack in a larger amount of properly moist tobacco.
It’s likely straight Carolina bright leaf. Enjoy it.
The Velvet is Kentucky burley flavored with maple sugar. Stick a little apple slice or one of those moisturizer coins in the tin, and after a awhile enjoy that too.
I think most old unused tobacco like those treasures come from the inventory of closed stores.
But alas, those things are silent, and can’t tell us.
They can’t even say a mumbling word.