There is some very nice stuff there, Sir.
I like the Albatri in particular. Even the Nieuport that seems to have had an unfortunate encounter is well finished.
When you speak of varnish going off, I presume you mean a matte clear? These can leave a frosty effect if too thick, or thickly applied. I sweat each time I apply one. Did you paint over the color again, and leave the decals? I av had some luck fixing 'matte frost' by applying a thin gloss coat (more specifically, Future, the magic floor covering turned modeller's aid), and also with a bi of a rub down with a polishing pad (3000 grit, from an auto supply store).
I will often go over decals with various washes, to get them less stark. Black decals particularly will benefit from being gone over with a dark grey wash, and rubbed down a bit with the pad.