Not mentioning the feact that the three surviving cars of 1966 were what was left of a flotillia of 8 MKII's that started the race.....
I have read that Quenting Spurrung once stated in one of his books that Ford had entered 15 (!) cars of which 8 were eventually accepted.....
Henri
Stefan Ornerdal's listings show eleven Ford GTs - a J, plus Mk1s and Mk2s - variously DNA or 'not accepted'. Not all obviously works-backed though.
http://www.formula2.net/1966.htm