Thanks to all who responded off list. It seems that foolish race photographers were always more interested in racing action and riders than equipment. After straining to find any actual photos in my books of the TDF and other races I came up blank for a definitive corroborative photo.
The best evidence was a clipping sent to me by Oscar Casander of a page from "Le Cycle" showing new products making their formal debuts in the 1970 model year Salons - including a Rebour illustration. And, the following Rebour illustration shows 1967 TDF winner Roger Pingeon's later but very similar 1969 race bike... still mounted with the earlier mod. 63 cranks.
So, looks like 1969-1970 would be the closest estimate to when the 93 may have begun to make an appearance anywhere. A surprise to me. I thought they were earlier.
http://farm3.static.flickr.com/
BOB HANSON, ALBUQUERQUE, NEW MEXICO, USA
**************************************See AOL's top rated recipes (http://food.aol.com/top-rated-recipes?NCID=aoltop00030000000004)