All generally accepted information says that there were 9887 Europas made. So subtracting all other models,

9887 - 295 S1 = 9592 - 243 S1A = 9349 - 103 S1B = 9246 - 1567 TC = 7679 - 3383 TCS = 4296 S2

Of the 4296 S2's the following is generally accepted:

417 were "P" suffix cars

426 were "Q" suffix cars

1291 were "R" suffix cars (and some of these were "PR" suffix cars)

Thus, of the 4296 S2's, 2134 were "Suffix" cars built after 1/1/1970.

This leaves 2162 early S2's of either Type 54 or Type 65.

According to registry data from 12/19/07, there were 306 registered Type 54xxxx cars and 64 Type 65xxxx cars.

This means that, of the 370 registered early S2's, 17.2% are Type 65xxxx and the remaining are Type 54xxxx.

Based solely on this mathematical relationship, since there is no other available build data,

there were 372 Type 65xxxx (2160 x 17.2%) cars and the remaining 1788 (2160 - 372) were Type 54xxxx.

I welcome information that might improve the accuracy of this estimation.