so this in your left slot would be as if the ring in your right slot was also put in the left slot
This was the hold-up with Shav's Revelation which was a new hot unique back then. It would just double the "granted" mods that the item gave you and was totally busted.
Sounds like this works pretty much exactly how I wanted, although mine was going to spawn on any ring base and only dupe if your other ring was the same base. I thought that was a cool mechanic for trading them around. They just gave this one a blank base.
It needs the blank base - part of how we were able to get this version working is it can't grant any stats of it's own, so any implicit it granted wouldn't actually work. This item is treated as the other item, instead of itself.