Hi, new guy here.
Steve posted about this thread on the P-51SIG, here's what I answered:


These four pictures caught my attention:







They show the selector and the control units of a SCR-595 IFF set.
Two things are interesting to me:
1- While listed as a possible IFF set for the A-36's and P-51A's I had never seen any evidence indicating the SCR-595 was actually used, I always assumed the better know SCR-695 was used instead.
The earlier SCR-515 and SCR-535 are also listed as potential IFF set for Allisons but I'm quite sure they were never used.
2- The units shown have Navy designations, so this set is officially an ABK (Mk.III) instead of an SCR-595, they are the same thing.
It looks like the gunsights are not the only pieces of Mustang equipment that could be switched between the Navy and USAAF.

Here's what an SCR-595 set looks like, you can recognize the two smaller unit from the pictures above: