Yep, they are a full set of genuine USA made Sperzel Locking Tuners, I'm thinking that their quality control may have slipped a bit, or maybe I was just unlucky enough to get a dud set, the tuners do turn smoothly, it's just that they all exhibit about 1/8th of a turn of backlash, from reading what they said on their website, these Sperzel tuners are supposed to have minimal end-play, backlash, and tuner-shaft wobble, I don't think it's the nut that's causing the trouble cause it seems to have been cut correctly, all the strings ring-out with no sitar-buzzing, and the 1st fret action seems all good too, it's definitely the tuners that are at fault, unfortunately it's been a bit too long for me to get them replaced under warranty.
I know that they are genuine USA Sperzels since they have "USA" stamped on them, besides, they look too genuine to be fakes.
I've got a set of new 3-A-Side Kluson Revolution Locking Tuners installed on my LP Studio guitar that I recently bought, at the moment they are exhibiting practically no noticeable backlash in comparison to the Sperzels, and they seem to be doing a bit better job in keeping the LP Studio in tune.