The only thing I've done to my R92 is work the action a couple of hundred times. That, and some lube, worked wonders. I changed the ejection spring to a hardware store one and that also seemed to reduce the amount of force necessary to work the action. Another benefit is it now drops empties at my feet instead of 10 feet away. Several U-tube videos online to show you how to change it.
The spring is a Century C-530, available on Amazon, pack of 6 for $5 with free shipping. https://www.amazon.com/CENTURY-C-530...s=century+c530
I see on Ebay vendors are selling a Uberti part by Taylor for '73's, a stainless magazine follower for .357. It's $11.50 with free shipping and I believe that would work in the .357 R92. They also have one for .45's. I made a follower from 2 empty cartridges or I'd be tempted to find out at that price. Even if it works well, that yellow plastic follower is ugly. lol
http://www.ebay.com/itm/73-and-66-st...0AAOSwRoxXnR~x
http://www.ebay.com/itm/73-and-66-st...wAAOSwRoxXnR7R