I've been trying to figure out if the following is a RS47b or RS48b (imperforate or die-cut):
What has given me pause is the top/bottom corners at the center don't line up vertically. If it was trimmed it is very close to die-cut (I have three RS48's including the pink which is only listed as die-cut). On the others the center corners line up.
I guess a related (key?) question is how consistent are die-cut stamps from that era?
Note that even if this was originally an imperforate that was trimmed, it would certainly not be worth the imperforate price. For me it's more a curiosity question.