Thanks for the link Jeff. I have no problem with my build being used for inspiration. That's what this forum is for.
It looks to me as if the aircraft presently has a reflector gunsight installed, which is incorrect for SL721 which should have had a gyroscopic sight installed. The wartime shots aren't very clear, but they're also not applicable to this particular plane, as that plane was TB886. SL721 has been painted by it's present owner to represent a plane (AU-J, TB886) previously flown by 421 Squadron RCAF. TB886 was originally delivered to 33 Maintenance Unit on 15-3-45, then went to 421 Sqdn RCAF on 19-4-45. It later went to the Royal Hellenic Air Force on 27-7-49, and is presumed written off.
SL721 was originally delivered to 6 MU 27-8-45, then Fighter Command Communications Squadron on 10-10-46, then to Vickers Armstrong South Marston 29-10-46 where it was nominally attached to the Meteoroligical flight, for use by AM Sir James Robb, until being delivered back to VASM on 17-7-48 where it was given a "special finish" and the gun bays were removed and converted to luggage compartments. Delivered back to FCCS on 17-12-48, but came back to VASM in February 1949 and repainted again, with further modifications. Returned nominally to the care of 31 Sqdn 11-4-49 for use again by AM Sir James Robb, now AOC Fighter Command until put into storage 4-8-51 when he retired. It was declared non effective scrap on 13-12-54 and sold to F Wilensk 11-2-55 and soon after became promotional vehicle for garage owner Michael Willcox, then it became "the Rose Garden Spitfire" at Beaulieu Motor Museum in the New Forrest area in England. In 1966 it was sold and went to the USA, registered N8R. Later on, it came back to England as G-BAUP, then went back to the USA as N8WK, where it was given Battle of Britain camouflage with the letters JM-R as squadron codes. In 1977, it was sold to Woodson K Woods and given the squadron codes WK-W, then in 1991 his son Chris restored it to the way it was in 1948/49 when flown by Air Marshall Sir James Robb. In 2000, it was sold to Michael Potter in Ottawa and subsequently it was repainted as TB886, AU-J of 421 squadron RCAF as flown by Flt LT. William Harper. As flown by Harper, TB886 was named Dorothy II, but the owner decided to paint SL721 with the squadron logo of an Indian head. TB886 was the first low back Spitfire to fly with 421 Sqdn, but never received the squadron logo. TB886 was used on operations during the final weeks of WW2, whereas SL721 was built after the war in Europe had finished.
I now believe that the "special finish" applied to SL721 was something a little darker than RAF Azzure blue, but it was definitely not PRU blue, although it was painted in Scheme D PRU light blue later, probably February 1949. As painted by Chris Woods, it appears to be a blue very close to RAF Azzure, and the spinner is painted white/dark blue, which may be an attempt to recreate the plane as it was between 17-7-48 and February 1949. What photos I can find of it in this period do not appear to show a gunsight being fitted at this time, so I'm still thinking I will leave this part out. The white/dark blue spinner was also not applied to SL721 when in RAF service.
However, I'm still researching, so the final result of this build may be a little different to my present thinking.