Great, thanks! 12+19 Windows. Every pic of 98-6006 seems to have this config, like N610G, which hasn't flown since 22jul.
02-5001 Has been flying almost on a daily basis the whole year. N226G flew between 21jul and 17aug so during that time 02-5001 should have been N610G, later N226G again.
I am starting to think that since 98-6006 showed up in 2013 it is always N610G, and 99-6143 is always N226G. Before mid2013 99-6143 was seen with both window configs, after that only 13+17.
98-6006 was used shortly in 2000, probably on N757AV, the aircraft that later became 02-4452. In that case clever to use that number again in 2013 to confuse us even more.
02-5001 Seems to stay in the US and still swaps regulary between the two frames. E.g. pics of 10dec15 show 12+19 windows, 25sep16 13+17, 26apr17 12+19, and 05jul17 13+17 again.