Hi Kirill. PVs didn't usually carry the Navy designators on the tail as with other types. Sometimes the last 4 numbers of the BuNo. were in white behind the cockpit; but it was common to mark the last 2 numbers on the rudder in white as "47" in this photo ( the first PV-2 had "01" on there) eg. 34920 had "20".
No.30 COULD be 48930 lost June 14 1944 in Russia; from VB-135.
Nick
http://torikai.starfree.jp/aircraft/ventura.html