I was not aware that the batches we had under the MDAP, had the MAD tailboom but just the early versions without or with turret?
The first batch of RAAF Neptunes for Australia in 1951 were P2V-5s (before the P2V-7s a decade later) and were in an early configuration similar to this, but not quite.
The first were what we referred to as the Mark 1: three gun turrets (nose, tail, mid upper), no tailboom, no jets. Later the nose guns were removed.
The Mark 2, removal of nose and tail gun positions, addition of MAD boom and clear nose.
The Mark 3, removal of dorsal turret, so looking more like the final variant - MAD boom, no guns, clear nose cone.
Mark 4, the P2V-5F, in 1959 modded with J34 jets under the wings.
After the 1962 US designation changes, these became the P-2E, some say the SP-2E. The P2V-7 was delivered as the SP-2H.