I might as well throw my 2 cents in here as well. Looking at my TO131MZ L35 Jan. 31, 67 dipstick, it looks exactly like Mike's TO214 MZ dipstick with the same bends. (Top picture in his post.) As well as the same markings, no lines just 2 dots with the "M" that looks like an upside down "W" and measures 18 and one eighth inches from the top of the "bell" to the add mark. Unfortunately the button is missing. The top portion is painted black. Don't know if someone did that or not but it looks like it has been there a very long time. I wonder if there were differences in the MZ California A.I.R. verses others?