For a pretty good summary of the various Neptunes, click HERE
Since the Japan Maritime Self Defense Force utilized the P2V-7, it was appropriate for a Japanese plastic model-kit manufacturer to produce one in this configuration. It was first released in 1972 and has been frequently reissued with different decals. While some of configuration details, notably the canopy, are unique to the -7, "cottage-industry" conversion kit manufacturers have provided the details necessary to backdate the -7 to the -5. See http://tailspintopics.blogspot.com/2020/03/lockheed-p2v-5-vs-7-neptune.html
However, my main interest in the Neptune is that the Navy optimized a handful for a very specific mission after World War II, the delivery of a nuclear weapon from an aircraft carrier. This was the P2V-3C. While the conversion to a -3 is more extensive than creating a -5 from the -7, it is not a significantly higher degree of difficulty. For a detailed -3 conversion build-article by Edward Ellickson, aka TheRealMrEd, click HERE. It is profusely illustrated. Even though you may not be interested in a P2V-3 model, it is entertaining and informative, with lots of modeling tips and descriptions of a few problems necessitating creative solutions. Moreover, unlike some of us (me for one), Ed completes his challenging projects.
Edward Ellickson model and photo
The initial plan was to recover it back aboard by the usual means, but after an evaluation of the degree of difficulty during field-landing trials at Patuxent River, the tailhooks were removed and the operational concept was to crane the P2V-3Cs aboard when required. This picture was taken during the tailhook proof-load testing at Lockheed.