There's no way you're going to make a 2-seat RADAR equipped night fighter out of a P-51. For one thing, the only place to put all that extra gear is behind the pilot, displacing the fuselage tank - and your RADAR Observer. It might have been possible to hang an AN/APS-6 or AN/APS-19 "Bomb" on one ot the wing racks, like the Navy did, but you still need electricity for it, and a place to put the radar scope and controls. Not much room in a Mustang fuselage for that.
Oh, and 4th Fighter Group was a Day Fighter unit. Those antennae look more like a Radio Compass setup.
The F-82 would have been great, once they got it all working. The initial prototypes and early production models (The 20 P-82Bs, and the single C and D Night Fighter conversions) did have Packard Merlins - V1650-23/25s with ADI injection. The problem was, at the end of the War, the co-production agreement with Rolls expired, and there weren't going to be any more Merlins. Allison had the 2-stage (Integral main stage and hydraulically driven aux stage, with intercooler G series (V1710-143/145) They had great potential, but Allison had higher priority on the J33 and J35 jet engine projects, and getting the V1710Gs in shape was a long effort to sort out the highly stressed beast.
Of the Allison F-82s, (Designation change in the Air Force in mid-1948) the F-82Es were long range escorts, and the F-82F and G Models were dedicated Night Fighters. All came into service at about the same time, the -82Fs and Gs replacing F-61s, entering service in late 1948. When they worked, they did well - Japan based F-82s were the primary air-air fighters in the early days of the Korean War, when the NKPAF was cleared out in short order. (The F-80s in the day fighter squadrons didn't have the loiter time when operating from Japan) However, when the F-94s became available in 1950, they were dropped like hot potatoes. The E models flew with the 27th Fighter Escort Group in SAC, and were replaced by F-84s in 1950.
If there were P-82s available in 1945, they'd have been Merlin powered, and they'd have done well. But the first Twin Mustang didn't fly until July 1945. Since there weren't a whole lot of targets for it from late 1944 on...