I did this setup on mine:
https://www.gohunt.com/read/skills/increased-accuracy-from-an-open-sight-muzzleloader#gs.18xgm5 Except I used the Peeprib. The Peeprib has what appears to be the same Williams sight (or an exact knockoff of it) as part of it.
I used Marble front dovetail mount, 0.1" height, to fit 0.875" barrel size for the CVA. Lyman front globe, and Lee Shaver insert the crosshairs one. I painted the crosshairs with Glow-On gunsight paint, and that really helps in low light visibility (for early morning hours, charge it with a headlamp beam for a bit).