I will try to answer the questions, first of all, excuse my English.
Regarding the painting, a nice mixture ... for the brown I used H-83 and H-63 and cleared up with the White Mr Color 316. The green resulted from the combination of the H-78, H-84 and H -155. I do not remember the percentages, but I must have them written down. The lower part is Mr Color 316 and H-147.
You're right about the kit, it's my favorite too, but you have to work it a lot. Begin by re-scribing all the panels. The windshield issue tries to disguise it as best as possible, but it is a license.
The conversion of those 6.25mm is done just with the other parts of the kit that you say, and tons of putty.
The engine cover is cut out of the kit and carefully reduced with dremel, because I did not like working with resin.
The nose cone and the RWR sensors are from the wingman kit. I did not put the tank on it because I wanted to do it with the cleanest configuration.
I have the honor of living in Tandil city, where the 6th Air Brigade is located. Unfortunately, since 2015 we no longer hear the Deltas as they finished their service after 130,000 hours of flight.
I hope I have been helpful!!