When Gretsch switched from 3ply to 6ply they added silver sealer around that time. Most Gretsch people agree that was around 1958.
I guess I am in the minority on this. I think that the interior sealer and the ply switch are very separate happenings. From what I have seen, most of the unpainted 3-ply shells with date stamps are from 1954 or earlier. The latest stamp I have seen in May 1954. (If there are later date stamps, I would be very interested in them.) So, if the silver sealer started in 1954, this would mean that there are about four years of 3-ply drums with painted interiors before the switch to six plies in 1958 as Kona suggests. There would then be another four years of 6-ply drums with painted interiors before the labels started, in around 1962. None of this is exact at this stage, but that is what I use as a timeline.
relayer - Your snare has one of the later style Skinny Stick badges. I have not yet been able to put dates to when each style of badge was used, it is not inconsistent with a 1950s drum.
Rick