Both were/are products of Key Publishing, who produce one of the two main historic magazines in the UK,
FlyPast.
Air Enthusiast was a very good magazine, and often focused on more obscure subjects which were possibly a little too niche for a mainstream title. It is a very good read, and generally it features mainly historic items with only a few pages devoted to "news". Worth buying even now if they are cheap.
Air International is more mainstream magazine, and covers both contemporary civil and military topics, placing itself between a title such as Key's
Air Forces Monthly and some of the purely "civil" magazines (which I can't name as I don't read them!).
