Best ask Phil. He has the database. Some of it says whether a car was scrapped or crushed. I don't know how you can expect to get more than an estimate on this figure.
I have had a total of twelve 1969 convertibles; 11 were XR7's (two 428CJ Ram-Airs, one non-Ram-Air, eight were 2V or 4V 351 cars) and one was a non-XR7 (a STD 428 CJ Ram-Air). Three of the eight 351's were parts cars, all now scrapped.