According to Keith Rylatt's "Groovesville U.S.A", the label was owned by Tony Ewing. I have 2 singles on Chex (#1007 and #1010) both written
by a W. Ewing that use the same stamper with "D. J. Copies Not For Sale" in the same spot as the Poptone release.
If you check on Collector's Frenzy, quite a few copies have shown up over the years.