The English Gastons that I've got are all from when Fantasio used to be Gaston's foil. The strip got funnier when Fanta left and Lebrac inherited his role, but at the same time the puns and jokes got much more complicated to translate. So I've translated into English only Fantasio era strips.
*goes to check* There's about 80 strips that I've translated into English, and a handful of other Gaston-related stuff (one-image gags, the pages where Fantasio leaves the office, etc).