All I can say from the pics is that it's from '59 to '64, and it's a six-cylinder car; the longer front end means you'll have more room for an engine swap. These cars are unibodies with subframes holding the front and rear suspensions, so if the rockers and floors are rusted away, so is most of the original structure. I'm sure you could bring back some of the "fintail's" famous, rally-winning structural strength with some patching and a big, bad roll cage, but you might be better off putting the body on some other frame. As much as the Benz enthusiast in me hates to admit it, a fintail body channeled over a Crown Vic's structure would be a hell of a LeMon, and way better for the race than an original fintail.
By the way, Lemons old-timers might remember Judge Ed's Field Find Mercedes, a '65 190 that won People's Choice twice. It was also a hell of a LeMon. Big, heavy car? Check. Small, single-carb four-banger? Check. Swing-axle rear suspension? Check. Column-shifted four-speed manual? Check-mate, baby. That's what Lemons is all about.