Never seen them before, but a quick search here
https://www.hungarianstamps.com/201...f-1918-1920/ produced a paragraph that includes the following: "Some examples of municipalities that are included in the category of locals issues are: Zombor, Ada, Nagyszeben, Kluj, Pancsova, Perlak, Baranya III, Skalica, Lajtabansag (Western Hungary) and several others" Since your stamps are postmarked Pancsova and Nagyszeben, 1923-4, I'm guessing that the overprints could be local only. Both the overprint and the dates indicated that these are stamps of the royal restoration, i.e., the regime of Miklos Horthy.