The only airgun I know of bearing the number "335" is by Anschutz, an excellent medium-power barrel-cocking sporter with a locked breech. It was a contemporary, and competitor, of the FWB 124. There were a couple of versions of it, the latter sold here by Crosman as the "Crosman Challenger 6500."
However, I suspect that you are looking at instead, a Winchester model 333. This is a re-badged Diana model 65, a barrel-cocking, recoilless match rifle, also with a breech locking lever as luck would have it.
Along with a wide variety of Diana sporter airguns, these were imported by Winchester approx 1969 to 1975. A few examples of the Diana model 66 (same action, different stock) may also have been sold under the Winchester 333 name, and the 66 stock was sold by Winchester as a replacement component.
In really nice shape a 65/66/333 is about a $400 gun. It is typical for these to need rebuilding, the original piston seals have a definite propensity to disintegration.
Pictured below, an Anschutz 335.
The 333 has similar lines to the slightly earlier Diana model 60, seen here.
