I see no indications of a re-entry...I see a lot of heavy over inking and ink smears...When I was working as a lithography for years, this happen a lot on a run until you got the ink distribution correct...I have a few stamps around the same year that look like what you have here..I almost guarantee you DO NOT have a re-entry...But why dont you send your scans to Ralph at
www.re-entries.com...He is the expert..He will tell you one way or another if you have a genuine re-entry.
P.S. if indeed they used Linotype slugs on platnam presses back then (which I think they did)..It was no unheard of to see even postcards, brochures and other forms of printing to have the same effect that you have on this stamp.
P.S. Linotype slugs are individual slugs .918 inches long with letters or numbers at one end for printing purposes.