634557/558: Similar to 631548/549 except for the embossed "S T" at the center hole on the B side label, font differences and the copyright information printed along the rim of the each of the labels. This would be a third variation I've rounded up. There are still two others which await suitable examples for posting.
I've seen two additional variations. However, neither are complete sets and are of such poor quality that they really aren't worth bothering with. Unless I'm filling in to complete a set for someone who has failed to post either an A or B side label, I don't post material until I have the complete set. It saves a lot of headaches for someone else to search out the mate and it provides any researcher or collector interested in the entry a clear graphic representation of exactly what to look for on both sides to determine its validity as a proper and true pressing.