Help: Steve Morse Y2D locking nut replacement

I own a Steve Morse Y2D with the Music Man® double locking tremolo.
I just found that the B and E string has worn down into the locking nut so that the 2 strings no longer are fixet to the locking nut.

I want to replace the locking nut but don’t know what spare part to order.
Is it a Schaller or a Floyd Rose part?

Has any of you experienced this before, and what new locing nut shall I order?

//John