Here are the 3 Coupon backs lined up. I started collecting all 3 series in the mid 80's b/c my Dad was paying and he said these T213's were just as good or better than T206 and looked exactly the same. I think he was right.
It's easy to find a T213-2, but may become difficult when you are looking for a specific card. I have 3/4 of the Tinkers and the 4th one was in LOTG and is a key to the set. I was the underbidder and the winner got a great deal I thought.
T213-3 are hard to find. More difficult than 2 series by a wide margin. T213-1 are very scarce. If they were a T206 I would say between Carolina Brights & Uzit as to difficulty level. As Mr. Z stated earlier, T213-1 has 68 cards to the set.