Finding a great 335 is a worthwhile experience. Some are truly awful. Great ones are sensational. Play as many as you can. I stumbled across mine by accident, and it is now my #1 stage guitar. They are somewhat "swiss army guitars" that cover a lot of territory ... however ... to do this I have changed the pickups, with a DiMarzio SD in the neck and a GFS "P90" - esq type in the neck for brighter rhythm tones. This makes it much more versatile. Some models have maple necks (etc) and these are fine too. As with any guitar, but particularly the 335, go and play as many as you can. When you strike "gold" you will know it. Mine has a thinner neck, and medium weight. All fine by me. Any vintage has the potential to be good (or not so good) ... but the early ones are certainly something else.
A great instrument. I have a 1967 model. Ive also owned two 355s and two 345s. I sold them all and would hate to part with this. I like the narrow neck and the mellow tones. Mine has a bigsby and keeps tuning pretty good. Sounds as food as any fender but a little more fragile on those long haul flights so not one i would want to put in the hold of any aircraft.