I think all the manufacturing will have been 'outsourced' to ICM with Revell doing the distribution.
There was only one Mustang that was fitted with a RAF type 'spade grip'. IIRC it came from a Harvard. It was purely cosmetic and done to make it look more British when it was shown to the British Purchasing Commission. Photographs of the cockpit led to the erroneous idea that they were fitted to the first Alison-engined Mustangs. They were never fitted to production Mustangs.
The cockpit has always been a bit sparse and, I think, ICM added a few more bits from the AM kits. A small PE set is still available from Eduard which will enhance it but Part have a much more comprehensive set which includes canopy framing.
http://www.jadarhobby.pl/part-s48011-p51-mustang-mkiii-148-p-189.html?manufacturers_id=10 I am a little puzzled why they would choose FB145 as one of the decal options and then add invasion stripes. Certainly it would have had them but I don't recall any photographs of it in this guise, they date from May 1944 when the squadron were working up. I am pretty sure that the squadron badge would have been applied by D-Day and there should be a black letter 'F' under the nose. A better set of decals for FB145 can be found on Techmod's sheet 48002 which includes the letter 'F'.
It is noticeable that on a lot Polish Mustangs the Sky of the squadron codes is darker than the Sky band. It was difficult to squeeze a letter in between the roundel and the band and so one theory is that they added some black or Dark Green (which I would think the most likely choice) to darken the Sky so that it would not blend into the band. Perhaps that is the reason for the rather strange Sky of the decal sheet. Techmod's Sky is also darker that what it should be.
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