I can't find the old Column 5 site. I loved getting planes, terrains, and skins for SF1 back in the day.
some of it is on the wayback machine e.g. http://web.archive.org/web/20090819031459/http://www.column5.us/other.htm
& there is stuff at Combatace
Jane's USAF & the community (e.g. Terry at McFlys) were a big part of my life at one time - I even made it to the Dayton Airshow with some of them!