The International Cessna^® 170 Association

But if you've changed yours for later versions made of plastic...look out! NTSB is proposing an AD due to cracks. In the early 1960s, Cessna equipped a series of approximately 12,500 airplanes within certain blocks of serial numbers with the P/N 0513166 control wheel. This includes C-150's, 172's, 175's, 180's, 182's, 185's, and the 200 series aircraft, many of which may also provide "donor" control wheels for our 170's,

See the pics.

http://ntsb.gov/recs/letters/2006/A06_53.pdf

At first I didn't like the original control wheels, thinking they were oddly shaped and ergonomically backwards. Now I think a 170 without them looks...weird. I also didn't realize that those squarish control wheels from the eary 60's were made from acrylic, I assumed they were just cast aluminum like the 50's variety.