i had a 1966 casino (the al caiola signature version with no f holes). Great guitar. Losta twang. Nothing in common with a 335 really apart fromn the silhouette. Its more like a 125 TD in construction. Lotsa character. totally different bag of fish fromn the current epi casinos. Also have a look around for a gibson 330 - same axe really as the old casinos.
NOt a heap of bass - but it was pretty lively in terms of picking up feedback so thats prolly for the better. Having said that it was one of the most satisfying and responsive electrics i have played.
Check out Grant Green for some impossibly hip jazz tones from a 330 as an alternative to the obvious beatles/stones recordings.
http://www.youtube.com/watch?v=g0N_hd0drIc
Or even check out a recording of the theme from "Bonanza" by Al Caiola for a laugh!
http://www.youtube.com/watch?v=mjdRgBAY278
FTR....current casinos look good but are a world away from the old ones in terms of resonance and timbral variation...go to one of those vintage stores and you will see what i mean. A pickups swap will simply not get you there.
IN comparison to a 335....well 335s are semis and casinos are thinline hollows. 335 have hums and casinos have p90s. 335s are thicker sounding and more commonly used these days due tio their resistance to feedback, but the 300/casino is a sound you cant get anywhere else...so get both! lol