So, you want to buy a small body guitar, and the question is: What should I look for, why, and what are the upside/downsides to this?
First, please keep in mind that this is an extraordinarily subjective matter. And so that you have a way of checking out your 'subjective' opinion and perspectives, I recommend you play a bunch of small body guitars of different kinds: Martin, Gibson, and may others that are out there. I've seen some vintage small body guitars that are even rarer than Martin and Gibson that sound just as good, but they cost less because they don't have the demand from collectors that Martin and Gibson have. But unless you happen to be near Shoenberg Guitars in Tiberon, CA, you probably won't see many of these in a store where you can compare them. I suppose Gruhn, Elderly, Bernunzio, and a few other places that carry and are really knowledgeable about vintage small body guitars may have some of these, but you'll have to hunt for them. Heck, you have to hunt for the Martins and Gibsons these days. They haven't been a secret for a long time, and now everybody wants them. So there is a lot of market pressure on these, and they don't hang around in shops for long. Watch out for eBay...it is hard to buy a vintage guitar from a picture and somebody's description. I know of good and bad outcomes...and I prefer to see, touch, smell, and play them first. It is a big investment, and besides the money you are spending, if you are like me, you want to have a guitar you can fall in love with and keep falling in love with for years to come. If you are buying with the expectation of a good investment, I can't advise you. I'm a player, and yes, I have a collection of 3 vintage guitars. But mine are NOT investments; I play them all the time, and none are for sale or will be sale in the foreseeable future.
As far as vintage reproductions, I have seen some that I would love to own. Aaron Morris, a talented luthier here in the Piedmont area of NC, makes great small body guitars. Wayne Henderson in VA makes some nice ones, as well as several other custom builders. In fact, in California there are a dozen or more custom builders that can make awesome small body guitars that, even though brand new, sound amazing. I know that as the years go by these will mellow, round out, and open up to sound as good as the vintage Gibsons and Martins. But some of them cost double or triple what a vintage guitar costs, so why buy one? Hey, they are new and pristine, and you can get them customized. That is a reason to some.
I know people who want a guitar made just for them. I know pickers who want a nice, shiny, new guitar. I know people who are scared to death of the 'hidden' issues with old guitars, like neck-sets, bridges that pull up, braces that come unglued, etc. So why do I like the old ones? Well, I love history in general. I love antique stuff. I love the musty, dusty, musky, smell of the inside of a vintage guitar. I love wondering who played that old guitar for the 70 years before I bought it. I also think that many...NOT ALL...pre-war guitars by Martin and Gibson tend to have great tone and other qualities that I seek. But that is just me. So how 'bout you? It is one of those things you should ask yourself and be comfortable with before you plunk down several thousand dollars for the guitar that you want.