Antiques as an investment 40 years later: Kodak or Currier & Ives?

I've often wondered: if I buy antiques and collectibles instead of more traditional "assets", how am I likely to fare? I love old stuff: I like art, I like antiques, and I'd much rather spend my money on that stuff than on mutual funds. I recently looked at the tanking values of Precious Moments and Hummel figurines but what about other, less kitschy rarities?

Of course, there are plenty of indexes that track the performance of art. But the problem is that they tend to focus on really, really rare stuff. Sure, Picasso's and Rembrandt's have gone up in value but since I can't afford them, who cares?

I just stumbled upon a very cool opportunity to look at how prices for some less rare objects have changed since mid-1960s. At an auction, I purchased a large lot of vintage ephemera, including sixty-five auction catalogs for Parke-Bernet Galleries of New York, which was a leading auction house acquired by Sotheby's in 1964, and since folded into that company's operations. Inside each catalog, I found a print-out of the "prices realized" for each lot. I looked up a couple of the more interesting (and easy to find comparable items) on eBay and other sites to answer the question: How have mid-range antiques and collectibles held up as an investment over the years?