[canjond]

What we know is that cards were packaged with 10 count packs. Factory records indicated so. There's nothing that has come to light to show that cards were also packaged with 12 count packs which weren’t available until years later, and so absent some sort of proof that T206s were packaged well into the late teens, I don't believe it to be the case.

The pack pictured above was produced well after the T206-era. I can't see the exact date unless I see the series number on the pack, but it is not period correct.