I have posted this information online before, but I'm hoping reviving it here may add some new confirmations to the information I've been able to gather so far.
One of the more intriguing aspects of this scarce issue is the number of back variations considering the sets small size and limited production. The set was printed by Fulton Press which consisted of two brothers running a small print job shop out of their family home. Unlike large printing firms of the day that produced thousands of cards for issues like T206, the E222’s were produced in small batches and for a presumed short period of time.
One of the challenges in understanding the different back variations has been acquiring enough scan examples of each subject to understand the patterns. To date I have partial or full information on over forty unique cards from auction listings, posted scans and generous private collectors that have shared their information with me. The following is what I’ve been able to determine about the backs at this point.
1) There are six A.W.H. back variations and one A.W.A. for a total of seven different backs.
2) Each of the six A.W.H. backs was printed in red, blue or black.
3) All A.W.H. backs have a confirmed example with each of the three colors with the exception of back #3 black.
4) All three A.W.A. examples known at this time have blue backs.
5) Each back variation was printed with a pair of front images with the exception of back #5 which was printed using two pairs.
The following is based on 40 unique cards on my confirmed list and could change with newly discovered examples.
Back #1 - Lipe and Sieber are found with this back.
Back #2 - Guiheen and Hooker are found with this back.
Back #3 - Revelle and Shaughnessy are found with this back.
Back #4 - Smith and Titman are found with this back.
Back #5 - Two sets of pairs are found with this back. The first is McCauley and Ryan the only two subjects who have also been found with A.W.A. The second pair is Hooker and Shaughnessy.
Back #6 - Ison and Otey are found with this back.
Back #7 - McCauley and Ryan are found with this back.
Here is a breakdown of the 40 subjects on my confirmed list and the back variation and color for each.
I'd love to hear from anyone that has anything else to add, has a question or comment and again thank you to all those that have already helped a great deal by sharing their information with me.