Not sure if this is a curiosity or common.
Just picked up for collection a S35025 issue that is same on both sides, Velvelettes -These Things Will Keep Me Loving You. I have an issue with Since You've Been Loving Me as flip. This same-both-sides issue is EXACTLY the same label face as the standard issue A side, same matrix, stamped, label design. There are no prom markings, nothing to differentiate it from standard issue apart from same label and same track both sides. The new aquisition has same label stamp and scratch number both sides, the standard issue has different stamp and scratch number on either side.
I've got the swirl design DJ copy, same label and song both sides, that has a different stamp.
Seems to me to be a curiosity. Why a single song issue with no promo marks? Are these common?