The stocks I have seen on Vixens are only slightly better than those available on standard '35's.
Were the Vixen does differ is the internals. The piston is sleeved and the (longer) main spring, guide tube, and piston are matched and chrome (?) plated. http://smg.photobucket.com/user/Airs...tml?sort=4&o=9 They were advertised as guaranteed to do over 800 f.p.s. in .177!
The barrel catch is chromed and the word 'VIXEN' engraved on the barrel block. They also came with a special fleece lined gun bag.
http://smg.photobucket.com/user/Airs...ml?sort=6&o=52
Vixen advert: http://smg.photobucket.com/user/Airs...ml?sort=6&o=50
HTH
Ian