[NYHighlanderFan]

Hello everyone!
Has anyone ever seen a T206 with a factory stamp on the back of the card? I've seen Turkey Red cards with stamps on the backs. The one which comes to mind immediately is the Turkey Red automobile set.

I recently picked up a card which PSA graded a 4(MK). The (MK) is due to the date Nov 28, 1908 stamped on the back of the card.

When did the T206 cards go into printing?

When did they begin getting stuffed inside the packs?

Has anyone seen a date stamp on the back of any T206's and is there any significance to that date?