For the last eleven seasons, since the move to Sony, the wheel has had the same base template of spaces for the entire show, with only the top dollar, second bankrupt, prizes, and whatnot being added on or moved around. In fact, examining that Yahoo Photos page, there've only been two bases, and the second one, from 1999, only modified six spaces from the 96 base, five of them 250s. They changed the colors around this past season with the HD wheel, but the values stayed put. So for the past eleven seasons, the wheel's been using the same amounts for the whole show, with the current values in use for eight.
Before then, they switched out the entire wheel and each round had a distinctly different configuration. I liked that setup because there were more values that were closer to top dollar than 900 is to 2500, 3500, or 5000. But even though they did change things a bit, it was always just a few spaces here, a few spaces there, maybe change the colors around. But by looking at that Yahoo page, it seems that in 20 years, from 1976 to 1996, in daytime and nighttime, they never did a total wheel overhaul. In fact, comparing the 1976 daytime round 1 wheel to the 1995 nighttime round 1 wheel, 11 of the 24 spaces are the same value in the same spot. You always had 450 right after Lose a Turn, etc.
While I'm on the subject, anyone know offhand what the typeface is for the spaces on the wheel? I was making my own wheel in Inkscape, but I used Clarendon, even though I knew it wasn't exactly the same. (EDIT: I found it. It's Volta Bold. Now to find a freeware imitation...)