Oc 2824 adapter ring

Got my hands on a OC 1016 case and I’d like to use a 2824 on it. I understand drvintage has an adapter ring specifically for this.

“2824 Movement adapter ring for 31xx cases”

It’s affordable and no reason not to get it directly from him but for informational purposes (and always good to understand options), is this adapter ring specific to his cases and is this the only place to get it? (I searched myself but perhaps not using right words).

I’d guess it’s not unique and would be used in other gen’able cases (viet?) but I’m inexperienced in the vintage rep world.