I don't know how I missed this posting. This is a topic I happen to be fully versed on.... in fact, if it's Atari controller related, I seem to have it down.
Anyhow, I have a huge supply of Nyogel 779 (in 1oz) tubes AND Nyogel 779ZC (in 10gram tubes and 100gram tubes). I know everything about these two damping greases as I put a lot of time and effort into testing them, going over every last detail and putting both of them into real world use. The 100gram tubes are for internal use over here to lube up the controllers while building them.
Getting right down to it, essentially both of them are the same. However, 779ZC has a moly lubricant added to it. This added lubricant is meant to help aluminum on aluminum lubrication, however it has an added benefit of quieting down noisy plastic gears, too.
The 779ZC can be used in ANY application that requires 779. However, 779 cannot be used in any application that requires 779ZC.
So, the bottom line is that 779ZC is perfectly fine to use in any application where Atari has called out 779. I have tested this over and over and concluded that it's a perfect substitute. In fact, it works ever so slightly better since it's better at keeping plastic gears quiet.
I have many hundreds of the 10gram tubes of 779ZC in stock. I was planning to add these to my yoke (and 720, Lunar Lander, etc) rebuild kits sometime in the near future. The good news is that there will be no increase in my kit prices.
I was also planning on selling the 1oz tubes of regular Nyogel 779 individually for $15 shipped anywhere in the world. I have no idea if there's really any interest in these or not, but I went ahead and dropped the dough on them anyway. LOL If anything, it will make my rebuild kits that much more interesting.