There is no evidence I am aware of that any Panteras were sold to the public anywhere before spring of 1971.
The deal with Ford was signed September 9, 1969. They had a "rolling chassis" by March 1970, the yellow car that was photographed among the Roman ruins. That car was pushed from location to location. All the early reports about the car were just relaying technical information provided by the factory, none of the earliest magazine reports involved anybody actually driving one. A car was shipped to America and displayed at the New York & Los Angeles Auto Expos in April & May of 1970. There is no evidence this car was a running car.
To the best of my knowledge, the pushbutton Panteras, assembled at the Vignale Corrozeria in Turin, were ready for sale to the public just prior to or about the same time as the earliest Pre-L Panteras rolled off the assembly line at the DeTomaso Fossalta assembly plant outside Modena.
One of the very earliest Panteras, Bjorn Carlsson's pushbutton, chassis 1014, is listed on Ben Tyer's web site as a 1971 model.
The book Pantera Ultimate Portfolio, available from our club store, is a collection of magazine articles from 1970 to 2000. It contains most of the ealy magazine articles, which makes it a very good historical document.
cowboy from hell