Since you like 6 saddles, you might want that 6 saddle one instead; because you will likely find it impossible, with parts currently available, to switch the Pro II to six. And if you decide later you want 3-saddle, Kluson makes a hybrid that will convert that American Standard style 6 saddle bridge to 3.I can get either used for about the same price.
What model/range is the blue from 1993 ? Standard or pro?
I like the 6 saddles. Other than that, are they more or less equivalent?