On the Wheel of fortune wiki under the second pilot it state "While the puzzle board is designed to be mechanical, this element is not completed by the time of taping. Susan Stafford is hired to turn the letters"
Did they ever complete the mechanical element only to have it turn out to be too problematic? Sounds like if it worked Susan / Vanna would have only demoed prizes then.
Wheel of Fortune changes too much. My favorite theme is the "Big Wheels" from 1975-1983 and I miss the two bankrupts on the wheel ,current winnings displays behind the players, host and hostess on the center of the wheel at the end of the show , the wheel visible to the right when the puzzle board is shown , and the shots looking down at the wheel at the beginning and end of the shows.