Warwick Thumb NT6 Stacked Volume/Pan and Treble/Bass

Hey all!

I own a 2012 Thumb NT 6 that needs new stacked volume/balance and new stacked treble/bass pots. I've worked on the electronics of various Gibsons and Fenders but I'm a little out of my league here (gotta learn sometime!).

On top of that, I'd like the pots to be able accept the Hipshot O-ring knobs. I bought them for this bass and they do not fit on the current pots. They're designed for 6mm top and 8mm bottom. I guess I should've measured before ordering (oops).
Stacked O Ring Knobs

Can anyone point me in the direction of replacing them with the correct specs that will also fit the knobs?

Alternatively, I'm open to the idea of having a stacked volume-volume pot in place of volume/blend.

(FWIW the pots are getting noisy and need replaced, not just for aesthetic purposes)

Thanks!