Been doing some comparisons, I found that the P-51H wing is a bit different to the P-51D wing. Apart from not having the LERX, the whole leading edge is further forward from the main spar meaning it has a longer chords throughout. I found though, that the FJ1 Fury wing matches the F-51H wing and includes a LERX too, which is a bigger one than what the P-51D has. This would probably be a better option if I were to do another tri-gear P-51 as the wing already has the main gear in the right place.
I noticed that NA did quite a bit of re-positioning of parts when they designed the P-51H, the cockpit was raised up (about 6-8 inches) but the front of it remained the same distance from the rear of the spinner. However the rear fuselage was extended about 12" with the wing being moved back the same distance which gives the P-51H a longer nose look. I found this quite interesting ---
I've seen a few what-if's done with the F-82, making them as single fuselage versions. Jeff's idea of making his into a tri-gear is interesting but I think I'll make a couple of tail-draggers out of one of my kits. Only I'll use a Firefly Mk.IV nose on one of them (Griffon engine) and a Tempest Mk.I nose on the other (Sabre engine but converted to Sabre VII or VIII) but I'll shorten the rear fuselage a bit, so instead of being seven feet longer than a P-51D it'll be only about three and half feet longer. I'll use some P-51H tail planes as they are much bigger than the P-51D tail planes.
I've read that the F-82 outer wing panels were taken from the XP-51F/G (modified without u/c of course), and they also got used on the P-51H. Comparing the kit parts though, there's not very much the same about them, but sometime ago I had laid the Revell/Monogram parts over the 3-View found in 'Aircraft of the Fighting Powers' and saw that they matched very well.