My uncle flew P-39/P-400s from Guadalcanal, 67th FS… Always a favorite of mine, the 'Cobra… Looks like you’re off to a good start… I did side-by-side build log of the Eduard and Monogram P-39s a few months ago… (Guess which I preferred, lol)

Actually, that’s the IFF transmitter… The P-39/P-400 radios are in the fuselage… The IFF transmitter was only fitted to later-model USAAF variants, none on export version (Airacobra Mk I, Mk 1A, and P-400, AKA a “P-40 with a Zero behnd it”, according to Cactus Air Force pilots on Guadalcanal)…
The Eduard kit has a couple small issues though… The trailing edges of the wings were pretty thick and had to be sanded down closer to scale, and my copy had a big gap on one wing/fuselage joint, plus I thought the dihedral was rather flat… I tried to split the difference on the gap, but it wouldn’t line up right then, so I just filled the gap.
I had the Profi-pack, rather than the Weekend Edition tho… That version came with a fret of P/E parts, “weighted” tires, and fitted nose-weight… Didn’t use much P/E except for the cockpit parts and brake lines, since most of the rest were vent/intake screens, and were invisible, and if you looked into the intakes/vents, the styrene parts were well-textured anyway… I just drybrushed the screen-texture and saved the P/E screens for another kit another day…
One thing on the doors… The P-39’s left door could only be opened from inside, the right, from either in or out… The windows on the doors could be rolled down on the ground like a car-door, and I wanted to depict them that way… Didn’t get that option though, like the Monogram P-39 offers… Also didn’t like the lack of a nose-gunbay or any engine detail, and aside from the nosegear well and gear struts, the Monogram P-39 is, IMHO, superior to the Eduard kit in almost every way (I don’t care about panel lines-The just have to be in scale or easily made that way), although I liked the inclusion of the four-bladed prop & spinner for the P-39Q-21 models (No it’s not for some future P-63 release like some reviewers have written. The King Cobra was a totally different “Snake” and a bigger aircraft all-around.)…
Really nice work on the panel, seat-harness (Don’t forget the shoulder harness though) & hardware, and IFF cables… I’m looking forward to seeing more of your build-log, especially since you’re “popping your cherry” with this aircraft, so keep going! I could read about P-39s all day, especially since Uncle John flew them (Dad did too, but not in combat), and I think this aircraft just didn’t get the credit it really deserved…