Not sure if you were still looking for the answers, David, but...
I had a look on one of our 737-800's today and checked the number of clicks per revolution for the Airspeed/Mach selector and there were 36 clicks. On the V/s wheel there was a rather strange 29 clicks (I double checked this and came up with the same result). I have enclosed a shot of the MCP so you can compare it with yours.
Hope this helps.
All the best for 2003
Q.
http://members.ozemail.com.au/~b744e...37800NGMCP.jpg