1970s Air King: Black Dials and "T SWISS T" and "T SWISS MADE T" ?

[PR_]

Greetings!

This is my first post here at the forum :) (I'm a former watchuseek active member)

I got this ideia of getting me a vintage Air King as a self-reward for my first post-college job, next month and I just found some from timeman.
I'm looking at a black dialed 5500, from 1972-73.

My question is, how rare are this black dialed air king ?
Can some say "T SWISS T" and others say "T SWISS MADE T" ?
What is a fair price for once of this beautiful machines ?

Thank you for your help!
PR