Ted:
Sometimes the PX-10 came in Orange too. Also early PX-10 (not all) did not come with chrome rear stays. I will take some photos and get them to you of a 73' that I have restored . If you will get me some photos I will try to date it for you. There are some nuances with the crown, fork and how it is finished that give away the date. Also if you take a look at this website it give you some insight as to what you have. And in the end the french (god bless em) don't standardize much of anything as you probably know.
http://home.wanadoo.nl/
Jack (Giacomo-Francophile...how ever you spell it) Gabus Laguna Beach, CA jack@shermangabus.com