Posted By:
ElliotI'm with Scott B., I don't think it's a deliberate variation by the printers, rather just a different print run. I think what's interesting is the confirmation of the "Piedmont Primacy" theory as so far we've only seen the 150 Ritchey print run front on 150's and 2 350's, both Piedmont, but no other 350 backs. We should continue this research on other cards that had multiple front print runs and see whether or not it is only on Piedmont 350's where the earlier front is found.