Chick Hirashima was the last of the riding mechanics. I've posted about him before I'm pretty sure, but 7 or 8 years ago.
http://wildaboutcarsonline.com/members/AardvarkPublisherAttachments/9990410884316/1967-12_CL_Chick_Hirashima_Bio_1-6.pdf
https://revslib.stanford.edu/catalog/wq721fn5565