I ran into a guy at the Dallas Vintage Guitar Show in Dallas two years ago. He was a dealer in antique instruments, and when I went by his booth, at the end of the show he had left a handful of old hybrid instruments. (I think I talked about this in another banjo thread).

What he had done was take some good parts from old 4 strings and place newer 5 string necks on 'em. He did it because he couldn't salvage the antique value of the instruments, and didn't have as many 4 string neck available, and I reckon he also had a more saleable product with a 5 string. At any rate, the thre or four that I tried really had a first rate sound, and feel. The necks were early 20th century, and pots were mid and late 19th. The prices were between $300 and $400. Pretty good deals, too.