I'm a fan of '56, too! can't beat a thirteen panel! So coooooool....
Hmmm. 26' would be a Cruise/Overlander. 30' a Sovereign. Depends on where they measured from. Mine started as a 20', revised to a 22', revised to a 24', ended up being a 26' Custom Cruiser! 3100# sounds pretty light for a 30 footer. A serial# would help. Not enough info to make an informed decision here. Proceed with caution.
Pros/Cons depends on the selling price and how much $ you are willing to shell out. Beware of the "doesn't leak" "floor is solid" claims. Best guess for something with the old "sitting for alot of years possibly most of its life" status is frame rot. Worst case scenario (or maybe best case... if you "have a dream") is a master plan and lotsa $.
Or you could luck out! I would seek professional help. Don't get caught up in irrational exuberance. Unless you are into that sort of thing!
Gotta go check on the '67 now & give her a hug,
