Odie, I too hope that there will be a number of "what if" repaints made available for this model. Although it won't be 'in use' by default, I will be including a separate, 'armed' Navy model, that will have the gun sight reinstalled, guns un-capped, and ammunition loaded, for any possible "what if" repaints to be used with (so that they can have all of the 'in-service' items that were stripped from or covered over on 44-14017).
As far as I've found, the tail hook design and installation was never documented - neither drawings nor detailed images of the tail hook have ever been found. This is due to the fact that it wasn't a 'big operation', but just conducted and overseen by a select few individuals (engineers and pilots) within the Ship Experimental Unit, and no drawings would have needed to have been submitted to the Navy or North American, as the project pretty much ended just as soon as the trials were concluded. So everything is based off of the 6 or so images that are known to exist, showing the over-all aircraft, with one in particular showing the most clear details. It was a challenge to want to make sure that the reproduction would be as near to original as possible, with only the documentation and photos that are known to exist. I started by making sure to research tail hooks of that era, so that I had a good understanding as to their different designs and function. One of the 'break-throughs' came when I read from one of the guys involved with the program, that the SEU's favorite, most dependable tail hook was the one they designed for the SBD Dauntless, and he states that the tail hook used on the B-25H for the carrier trials was a SBD tail hook. Knowing this, I decided to model the SBD tail hook mount - and low and behold it fit just as you would imagine they would have fitted it, in the position it would have needed to have been in to be mounted to the bulkhead just aft of the tail wheel (there is just enough room to put it there and not play into the area of the tail gear well). It also takes on the same appearance of the tail hook mount seen in the known photos. For the other details seen on the tail hook, I was able to match up to details from other tail hooks - such as the wire connection/retainer which looks in photos to be similar, or the same, as used on SNJ tail hooks - having several detail photos of SNJ tail hooks, I simply copied this item as it is on those.
The most perplexing item that shows up in the photos of the original, was the lasso-type metal bar attachment at the base of the tail. It wasn't until I read up on catapult operations (WWII and after), that I found out that besides there being the shuttle attachment hook for a pendant strap hook-up (or two hooks, for a bridal strap hook-up), there would be another attachment at the rear of the aircraft, known as a holdback, where a break-away or quick release strap would be attached, designed to hold the aircraft in-place until the catapult was primed and the engine was at power, before releasing. This remains employed on Navy aircraft to this day.
When you look at the bottom of the rudder, there are a couple of cut-outs, which has been said was done to provide room for the tail hook end. However, as can be seen, the end of the tail hook didn't come close enough to have the need for that cut-out. It is my belief that the large cut-out likely originated earlier in the project, when a longer tail hook may have been fitted. There is a smaller cut-out at the forward base of the rudder to provide room for the holdback looped-bar.
Bob Elder wrote, from his notes, that all of the modifications only added just shy of 40 pounds to the airframe (which has been incorporated with this aircraft).
Here are all of the particular details of this aircraft, which all have been replicated: Tail hook, catapult hook (below firewall), holdback (base of tail), rudder base cut-outs, gun sight removed, guns kept but covered with standard-issue caps (no ammunition), taped-over camera port, stronger "block-tread" tires, and over-charged main gear oleos (to help prevent bouncing and the nose pitching over when landing), Navy ship-board chocks, and Navy headgear as Bob Elder was photographed wearing.
The 'fun' challenge comes with landing. As Bob Elder noted, the bulkhead that the tail hook was fitted to started to receive some cracking after making arrested landings at 90 mph or more (this was found while still earlier in the testing, back at Mustin Field), and so they had to land slower than 90 - the aircraft's stall speed was 82 mph though. As a result, Bob made all of the approaches at 85 mph. This was no problem for him, with the experience he had, but for novice pilots that would have been a problem. Landing the aircraft requires a constant curved approach, not unlike what is required with the Corsair. However, Bob Elder mentioned that the visibility over/around the nose was worse on the Hellcat and Corsair than it was on the Mustang. While it has also been stated by other individuals that the torque/p-factor on the P-51 was an issue, according to Bob, even though he mentioned the 'swing' in his reports from the project, he also mentioned that it was easy to keep it in check (and one has to remember that the same swing would have already been encountered with other Navy aircraft, like the Corsair and Hellcat, and that he and other experienced Navy pilots would have been accustom to it). So far I've been having success with getting the approach speed slower and slower - yesterday I was still at about 100 mph, and today I've been getting right about 90 mph. At these slow speeds, the nose has to come up quite a bit, to keep the aircraft from sinking, but it is also critical that when you land on the deck, that the tail is low enough in order for the tailhook to catch. Bob mentioned that, due to the tail hook length, or lack there of, compared with the static angle of the aicraft, that you couldn't risk having the tail off the deck when touching down, or it would be easy to travel right over the wires. In the one very dramatic photo of the aircraft landing on the deck of the Shangri-La, you can see the tail wheel about to touch down a second or so before the main wheels would have.