Starting at the original request, none of the RCAF Squadrons operating in the ETO were equipped with the Mustang Mk.IA or Mk.II. They only operated the Mustang Mk.I. However, a number of individual RCAF pilots were attached, as were pilots from the RAAF, RNZAF, PAF, and IAF, to RAF Squadrons that did operate the Mustang Mk.IA and the Mk.II.
In early 1944, as a part of the consolidation of available/operational Mustang Mk.I and Mk.IA aircraft in the Reconnaissance Wings of 83 Group and 84 Group of 2TAF, all the Squadrons operating Mustang Mk.I aircraft were placed within 39(Recce) Wing - 83 Group - which comprised No.168, No.414(RCAF) and No.430(RCAF) on Mustang Mk.I and No.400(RCAF) on Spitfire PR.XI; with 35(Recce) Wing - 84 Group - which comprised No.II(AC) Squadron and No.268 Squadron with Mustang Mk.IA INo.II(AC) Sqdn starting to re-equip with Mustang Mk.IIs in May 1944) and No.IV(AC) Squadron with Spitfire PR.XI aircraft.
The Aeromaster decals in Post 4, as do the photo descriptions in the Ducimus Camouflage & Markings publication in post 9 contain multiple errors. The Mustang Mk.I titled as being with No.400(RCAF) Squadron with the codes 63-X in yellow is actually an aircraft of No.41 OTU which was the OTU for Army Co-operation and Tactical Reconnaissance pilots. The subject aircraft serial is not recorded as ever having served with No.400(RCAF) Squadron. The source of this error seems to arise from a wartime caption of photos of a group of RCAF pilots destined for No.400(RCAF) Squadron with the Mustangs whilst they were at No.41 OTU.
The oft produced in profiles and decals FD472 'M' wearing reduced D-Day distinctive markings, not with No.168 Squadron, but with No.268 Squadron -had been since February 1944 and would remain so until struck of charge in late August 1944.
Photos as well in Post 10 - top left photo of Mustang Mk.I, No.168 Squadron RAF - this one cropped out of a quite well known photo of it over a French village with a British Armoured unit on the roads below near the Falaise Gap area August 1944. Top right, Mustang Mk.IA, most likely of No.268 Squadron RAF taken May 1944, before D-Day on a practice sortie over the UK. AG431 'D' is of No.16 Squadron RAF and shows F/O Doug Sampson RAAF beside the aircraft. Then the sequence of photos of what is supposed to be Mustang Mk.IA aircraft of No.168 Squadron, are all of No.268 Squadron RAF, all photos taken at RAF Odiham late July 1944, just before No.268 Squadron moved to an ALG in Normandy. The photos with the pilot in Mustang Mk.IA 'T' and the bottom with the staged shot of the groundcrew member near the rear window and pilot looking over the cockpit hood top section, you can't tell from those but he has a 'Canada' flash on his tunic shoulder. For a long time that led to the simple conclusion RCAF units must have operated the Mustang Mk.IA at some time. FAIL! Photo is of F/O 'Gibby' Gibson RCAF, one of the RCAF pilots attached to the RAF and flying with No.268 Squadron RAF at the time. Taken also late July 1944 at RAF Odiham.
Note too that the RAF camera mount for the recce camera was greatly simplified compared to that shown of the US version. See photos in Post 10 of 'S' and 'T'. And the recce camera did not just operate out to one side, it could be turned around to operate out to either port or starboard.
It is regularly recorded in the Operational Record Books of all the RAF Squadrons flying the Tac/R Mustangs over the beachead areas after D-Day, a number of 'blue on blue' incidents, primarily by USAAF aircraft, particularly by USAAF P-51s and P-47s, with a number of these resulting in losses. There are lesser recorded incidents of attacks by other RAF Squadrons, only a couple by Spitfires and Typhoons. The showing of roundels and use of evasion tactics semed to have a quicker result with RAF aircraft than it did with USAAF aircraft.