Some great information on collecting and restoring control wheels, yokes and columns has appeared in individual threads over time. Thought it might be worthwhile to start a dedicated thread on the topic since it might pop up more often in a search. I had posted about the differences in early and late B-17 control wheels in a different thread. I'm guessing it might get more views and comments in this thread. And perhaps entice others to post and ask questions about different control wheels.
From the 1940's through the 1970s most manufacturers of large military, airline and business aircraft also installed decorative caps in the center hubs of their wheels--which are have a collectors following themselves.
So...contrasts in control wheel design: Early B-17s (all from the model 299 prototype to partway through [I think] early B-17F production) had an entirely different look than the iconic design that followed it for the rest of B-17 production. It had a decidedly art-deco 1930s look to it and was also used in the passenger-airline version of the B17, the model 307. And this wheel design, in turn, was derived from the wheel used in the Boeing 247....the first "modern" airliner. Variations on the design theme of the later production B-17 wheel were used on the B-29, B-50 and C/KC-97 series of aircraft. Dimensionally, for width and spoke location, it's easy to see the influence that B-17 control wheel design had on both the B-47 and B-52 control wheels.