Total Sprint production for '68 was 2525 units. I haven't seen a breakdown of coupe vs convertible for 1968 but suspect that the number is between 300 and 400 based on other years and the usual conv. to coupe ratio of 1/6.
Fred Simmonds of GM was cited as a source for the 1969 Sprint production numbers, showing about 250 Sprint convertibles of which about 210 were manuals from what I remember. Maybe he has the '68 production numbers too. Apparently he's the one who found the old documentation that is the basis of PHS.
