From my limited research and understanding, the engine will perform somewhat better and get somewhat improved mileage with two or three well-tuned carbs than one. Is this incorrect? Of course I'm not expecting to fry tires with my flathead six that's otherwise unmodified, nor do I care to. It's interesting to me to try to coax a little more out of the little flatty and engage in some half-assed garage engineering and maybe learn a thing or two---just trying to enjoy my little hobby as I see fit.
As far as "puffing out my chest for the rest of the world to look at my car," I didn't buy it for anyone else but me, to satisfy myself. I couldn't care less if anyone ever looks at it. I'll never take it to a cruise night, and I'll never join a club. But, if someone gets off having the world look at their car, fantastic. Who does it hurt?
Investment? A 73 year old DeSoto is hardly an investment.
There's a wide variety of reasons why people have old cars, or engage in any number of extracurricular activities. The reasons are personal, and really none of my business. I can't imagine looking down my nose in a public forum at any of them.