Need to put a dot optic on my 22/45 series 2 (non D&T)

I can't remember where I found the rear sight dovetail to optic mount I used on a previous set up.
Suggestions?

I think this is it, https://www.midwayusa.com/product/1018663986

Maybe so. I think I tried a "JP" and found it only fits that specific brand of sight. I'll check my other 22/45's. I think one of them has a direct to dovetail interface. Yesterday was a boring day and I spent some time pawing through a box of scope bases/mounts looking for something that I apparently never had or I already used the part I was searching for on another project.

Here's a mount from Burris, for mounting their FastFire sight to a Ruger MK rear sight dovetail:
https://www.burrisoptics.com/mounting-systems/mounts-and-bases/fastfire-mounts

Will supposedly work with a couple models of Vortex red dots, as well.

Works well on my MKII, low profile and "clean." I paid about $30, after spending some time shopping around.

Yes Uncle Howie, that's the one I have. I finally located that pistol and it has a Burris FF2 mounted using the dovetail base. Probably why I couldn't find it in the "ring and base' box.
I have another of the little "auto on" dot optics on the way.