The F10 is a legend on it's own footprint...much regret selling mine.
However the final GC design (the GC went through several designs from the Itisa) predates the F10 by about 30 years although made up to the late 70s, early 80s....
The inner tent, a sort of squared off tipi tent can be used on its own and is waterproof, but 2 designs of fly were available, the extended as above or a shorter, "standard" one that covered the tent and no more.
They were available in 3 sizes, the "Minor", the Standard" and the "Major"......................