Jerry,
Not my direct area of expertise, but an area I've picked up information on as I've been researching the RAF Allison Mustangs is on the USAAF use of them, which adds to what Steve and Chris have provided above.
There is also a photo (or two?) around of a RAF Mustang Mk.1A during the fitting trials of the Malcolm Hood - interesting in that it looks to have a white datum line painted down the aircraft side in line with the thrust line for the aircraft, which would indicate it was filmed during flight trials. Flight trials would have looked at opening and closing hood in flight and emergency jettisoning of hood in flight, all filmed at specific parts of the trails program from an accompanying aircraft. Don't know if that film has survived.
On the USAAF front, 107th Tactical Reconnaissance Squadron of the 67th Tactical Reconnaissance Group (TRG) based at Membury in the UK were equipped with 24 F-6Bs (P-51As with K24 cameras) in October 1943, initially with the 8th Air Force, but soon transferred to the 9th Air Force, flew their first Popular sorties on 20 December 1943. Squadron codes AX. Known aircraft AX-K 36174, AX-B 36046 "Little Sir Echo II", AX-G (see below) and AX-L 36185. Aircraft in few photos around typically olive drab upper surfaces over neutral grey under surfaces camo, usual US national markings, some seen with the white id bands, some without, also some in full D-day stripes. Accurate Miniatures re-released their P-51A kit in the markings of an aircraft from this unit (AX-B) and one of the early Aeromaster decal sheet also had one (AX-L) as a subject. 109th TRS also in 67th TRG had F-6s, Squadron code VX, but not sure if they had F-6Bs or later Merlin engined C's, need to dig some more.
For something interesting on 107th TRS, see here:
http://www.flickr.com/photos/thenati...rd/4101102178/
The USAAF units performed similar tasks as the RAF Tac/R Mustang Squadrons, but concentrated on the areas that the US Army would be operating over following D-Day. After D-Day they operated solely in support of the US Army on the Continent. Interestingly enough, the RAF Tac/R Mustang units also operated in the initial stages of the D-Day beach head operations over areas where the US Army was operating, particularly in the areas adjacent to the British/US line of demarcation between their zones of operation.
A number of the F-6Bs of the 107th TRS have been photographed with the Malcolm Hood fitted, similarly a few still with the original hood fitted.
They later used F-6Cs (P-51B/Cs fitted for Tac/R use) and F-6Ds.
F-6A was the original 35 (34? some number disagreement in sources on how many converted) P-51 (4 x 20mm cannon variant) modified and used by the 111th TRS in Tunisian, Sicily and Italian campaigns, and the 154th Observation Squadron in Morocco and Tunisian campaign, again largely in support of US Army units. None of these that I am aware of were modified with the Malcolm Hood.
"Patton's Eyes in the Sky" by Tom Irving has some information on the USAAF Tac/R Mustangs in Europe, one photo of a 67TRG F-6B from a quick scan through it coded AX-G on page 23 - can't discern the tail serial on the photo. Also a few mentions in the Osprey US 9th Air Force and RAF Mustang Aces book.
There was a thread or two that were over on the P51SIG about F-6 Mustangs and the variants and modifications. Included a few photos and extracts from the US tech manuals. Unfortunately with the site hosting issues that saw the site disappear about a month ago that information now appears to be lost. Hopefully when the site is resurrected a lot of that material might get reposted or recreated by members of the forum.
Regards,