Roger is right, as usual. Weinmann center-pulls were standard on the P13-9 and P15-9 (there wasn't a P10 in '72). The first generation Campy side-pulls were optional on the P13-9, but according to the '72 Paramount order form were not an otion on the P15-9 because they wouldn't provide the necessary clearance for fenders (fenders were an option on the P15-9, but not an option on the P13-9).

The optional Campy side-pull brakes on a 1972 P13-9 would have been the 2040 group (2000 front, 2001 rear).