[78-L] Two different Sun Johnny Cash pressings

[Chris Kimmer]

I have two copies of Sun 241 I Walk The Line / Get Rhythm by Johnny Cash, and they are not identical. Both are shellac and have the same "written" matrices SUN U-190 or SUN U-191 in the wax on their respective side. However, one has W21CO stamped (i.e. not scratched in by hand like the matrix numbers) in the wax. This one with the stamping also has different text alignments on the labels. For instance, the Hi-Lo Music and BMI U191 lines are left-aligned on the one with the stamping and mis-aligned on the other and the spacing between the composer and artist credits differs on each. Is one simply a later Sun pressing, or did people bother to make juke box or other types of pressings of Johnny Cash records long after their initial release? In general, the stamped one has a better printed label. The letters are well-struck and not as fuzzy or bled as the other label, leading me to think its the later pressing, but I'm guessing since I know very little about Sun 78s or postwar pressings in general. Any info the list has is appreciated.
Thanks,
Chris