Which Producer other than...

Faiveley owns both Musigny and La Combe d’Orveau 1er Cru?

I am assuming you mean Musigny Grand Cru and Chambolles-Mussigny 1er Cru La Combre d’Orveau? Georges de Vogüé?

I mean Musigny Grand Cru, yes.
Great guess, but not the other Producer who owns/produces both Musigny Grand Cru and Combe d’Orveau 1er Cru.

Prieur?

Yes, Sir!
Bravo.
Thank you for playing.
I believe only a barrel is produced annually, and I have never seen wine commercialized in USA through authorized channels