One of the great marvel of Zemstvo collecting (and there are many of them) is that, despite the numerous specialized catalogues created up to now, LOTS of information is missing and many discoveries are still to be made. Of course, we need to be dedicated and, actually, passionated by this field in order to really 'suck up its juice'.
Gadiach Schmidt 33 - 3 kopecks olive yellow & brownish red, 1894 printing
SEWING MACHINE PERFORATION (Rouletted) - RRRR, probably unique
Recently I blogged about a scarce line perforated issue from Gadiach. The stamp above is a new discovery that I made not so long ago, while buying some gadiach stamps on the net. It is the 3 kopecks olive yellow & brownish red printing, 1894 edition, labelled as number 33 by both Schmidt and GPS.
As you would have already noticed, the stamp clearly shows some Sewing Machine Perforation, also called Rouletted Perforation. They were applied very casually (and rarely!) over some sheets of the following edition (1895 issue, Schmidt 35/37), and Schmidt records only the carmine rose & violet (S34) and blue green & carmine rose (S37) stamps. Both stamps are rated 'RR' (9 to 15 copies known). But the same Sewing Machine Perforation applied to the previous issue had never been recorded so far.
To give a clue about their scarcity, the Sewing Machine Perforation (on both the 1894 or 1895 stamps) was unheard of Oleg Fabergé himself; he had none in his collection.
It is quite unclear to me when and where these rouletted perf. have been applied; but, as an hypothesis, the very resemblance with the issues of Zenkov (also in the Poltava Gubernya) makes me feel that they could have been applied accidentally on some Gadiach sheets (and as such, very rarely!) by the printer in Poltava, while he was busy producing some stamps for the Zenkov district.
Readers are welcome to check their own stamps, and I wish them to find one of these rarities. You can post the results of your search as a comment here.