Black bezel on Broad Arrow coaxial 1957 321.10.42.50.01.001?

Hello there!

I've seen some discussions on the topic of putting a black bezel on a Broad Arrow - 321.10.42.50.01.001, however I haven't seen any final results or have been able to find what I would need to make the change.

Figured I would ask the group here and see if anyone knows what and where to find what I need.

Thank you in advance.