I have multiple here - you will discover they were in various series - so was like K3; K3 60; K3 60 B; K3 60 C, etc. - usually marked as "Made in El Paso" - some of the very later USA made ones - like K"X"-I - the "dash I" or "dash-II" were likely gas tight sealed and purged when made - often marked "Made in USA". It is my understanding that very best ever made would be K"X" dash I or II, with the word "MicroTrac" on the left side of top turret. Some time after Bill Weaver died, the brand name was bought by some corporation that also owns Bushnell, Redfield and Tasco brand names - most production moved off shore - so like "Weaver Classic" was no longer made in USA - about nothing whatever to do with the older "K" series.
You asked how they "track" - again - 30 and 40 years ago - sighting them in was "work" - like inside guts not really highly polished - so can sometimes turn turrets several clicks - cross hair does not move - no change in POI on target for group - as if "hung up" - move one more click and get 5 or 6 clicks worth of movement. Why you will see old dudes like me tapping on turrets with fired cartridge cases when "sighting in" - to try to "jar" the mechanism inside to move. Another "trick" - seems better to be turning turret "in" - not relying on the bias spring to "push" - so if you want to go "out" two clicks - go out 10 clicks, then go back in 8 clicks. YMMV. So, once "sighted in", did not often turn those turrets - they were rock solid permanent in my experience - but not for "twirling" the turret settings for each shot like modern scope might be.
As mentioned - earliest ones were not sealed - so if you hunt in cold - into and out of warm vehicle - going to get fogging on inside of the lenses - and that means condensation in there as well - leads to corrosion, etc. Not like modern stuff. But, to repeat - is my experience that once you are sighted in, it stays there for hundreds, if not thousands, of rounds. Your mileage may vary.
I am describing likely low powered - K2.5 through perhaps K6 - I do know they made higher magnification and target series, but I never used them. I do have one variable - a V9-II, that is marked MicroTrac.