Leon, let us know what the seller says, but the tin that one comes w/ basically only eliminates 1909 as a date--as I think it has the 1910 copyright around the rim on the lid.
Most of the known player selection doesn't really help us w/ dating. However, one of the players I have seen w/ this back is the Harry Hooper w/ Boston Nat'l (error card). I speculate that this was the first version of Hooper made as it was in error and they corrected him to Boston A.L.--this is also supported by the fact that I have an E270 Tin Top of Hooper w/ the exact same image & font as the (imo) later Boston A.L. version. It wouldn't make sense to me that they would do the AL version then switch to the NL only to go back to the AL--so it is likely how I laid it out in terms of a time line. Also, it is interesting that I own a Red Nelson (Toledo) w/ this back as he never actually played for that team--if he was signed by them at some point and that can be discovered it will likely be the best possible chance (as of now) to "date" when the 208's were made.
It is more likely that the "208" back was only produced as a small print run, otherwise there would be more of them. The fact that Hooper NL is found that way we essentially know it wasn't the last print run as they later made the AL version--and the AL version is significantly easier to find as well so there was a fair amount produced after the change. If I had to venture a guess based on all that I have seen I would say the 208's were produced at ~the mid-point of the E254 distribution (likely in 1910). I reserve the right to proven totally wrong at some later date!
Hooper Boston NL
Hooper Boston AL (E254)
Hooper Boston AL (E270)
