The output pinions carry identifying codes which which can tell you which diff input they are intended to match. These markings consist of concentric rings on the end of the pinion and sometimes a stamped figure. I do not know what this code means although it would be very useful to find out.
The official Peugeot workshop manual identifies the markings on the end of the pinion and on the crownwheel:
no ring - 16 x 63
one ring - 16 x 65
two rings - 17 x 63
three rings - 17 x 61
four rings - 17 x 59
Lasse H