As my interest increased in these various front/back permutations, I became thoroughly fascinated with the group of 63 subjects
in the series which we refer to as the
350/460 Series.
Illustrated here are the 22 tobacco advertisement backs that were printed on the T206 Subjects in the
350/460 Series.............
Note that all 22 of these backs were not equally printed on each of the 63 subjects. There is a "mutually-exclusive" factor in play.
460-type backs
.
............. Factory #42 .............
350-type backs
Assorted backs
OK guys, you serious T206 collectors.....why not chime in here with your stories ?
Does it get any more fascinating in this great hobby than
"Talkin' T206's" 
TED Z
T206 Reference
.