There are two profiles for this aircraft, and the bottom one should be deleted since the top one has a link to its other identity.
It was originally built as a PB4Y-2, but was later redesignated as a P4Y-2, and then in 1962 it was redesignated as P-4B.
The interesting thing about this plane is that it was registered under the BuNo 66304, but from what research I've come across it is really primarily 66261 but used parts from 66304 and 66313 to rebuild it and keep it airworthy while fighting forest/brush fires out of Greybull, WY