Posted By:
RichardTed -
No worries. We do have some good passionate discussions. 
You will find no argument from me about the T213-1 being part of the T206 set.
At the end of the day, what is included and not included under the T206 umbrella matters most to only T206 collectors. It also has a huge impact on valuation, as a "rarity" under the T206 umbrella is simply a rarity when compared to the rest of the mostly mass produced issue.
Take any of those rarities out from under the umbrella and their rarity disappears and their valuation along with it.
However, the argument could work the other way as well. If you were to break out your Sovereign 460 subset from under the T206 umbrella and give it its own independent ACC number, then maybe your Cobb Red Port would not get lost in the "just another back" shuffle and get the respect it deserves, along with the valuation is deserves as well.