VNB 1st OS Piston

Greetings from a cold and wintery Perth Western Australia.

Could you please confirm that this is the correct piston for a 1st OS 125 VNB? 52.7?

Piston Vespa 125 Super/150/T1
VNC1/VNL2T 30001-/VNL2T
100001-138956, 1st oversize
Art.-No. 87441000