Just a critique, the a/c has the "US applied" Red Stars, so, ergo, it would not have the outlines of the USAAF markings on it, because they would not have been there to begin with.
Ex. the P-63s in the photo in this thread, awaiting shipment to Russia. They have the Red Stars applied in the USA.
The evidence that "white 84" is a bird with the Red Star applied in the USA, is that there is no overspray of green on the fuselage where the red star is, so, it came with the a/c, unlike "white 23" (the default skin), which was obviously an example of one shipped with USAAF markings on it, that the Russians removed, as you can see the green paint they applied on the fuselage in that example to overpaint where they applied the red star after delivery.
On late war P-39s, you could have examples of both, but if the markings were applied at the factory, which many were, then no overspray, or US outlines. It depends on what exact P-39 you are looking at, and its a case by case study.
"P-39 Aces" page 81: "As wartime production increased and batches of a/c were earmarked for Russia while still on the production lines, a number of markings developments occured. Some a/c were finished at the Bell factory with Soviet insignia already applied, thus presenting the traditional Russian star painted directly on Olive Drab, with no blue circle, or Russian Green-overpainted background".
Filitovs P-39 "Yellow 93" was also an example of that type.
...Looks excellent overall.
PS I don't have a profile for "Brookyln Bum" or I would send it along.