I did, actually! The car needed a good wash, but the body looked to be in good shape. The paint has definitely aged more than the pictures make it seem, and it looks like there is some very slight surface rust on the verge of developing, but at this point it's just aesthetic and hardly even that. The owner informed me that the carbs desperately needed tuning, and that the plugs are all pretty much black right now. He was able to start it with the assistance of starting fluid, but the motor wouldn't stay running. Interior is also original and clean, but also looks pretty aged, the driver's seat was a little torn up. Dash was in great shape, just a small crack right above the glovebox. Also, the gas pedal was disconnected because it broke off, apparently, but he had a new one ready to put in. Also needs new tires, the ones on there have tread but they've been sitting for a long time and really dried up/cracked. Lastly, someone decided the car should be green, and started with a foot or two of paint on the left front fender, and then changed their mind apparently. He also has a new left front fender to throw on there, too. Most the rubber is actually in really good shape, with the exception of the passenger side door, still seals he says but it is pretty dried and cracked. He also has the replacement rubber for that. I snapped some extra pictures if anyone wants.
I've been looking around Southern California for a 510 in good shape, but I'm on the fence with this one. I definitely would want it repainted asap, and while the motor and carbs are supposedly pretty fresh, it makes me a little nervous that the car wasn't tuned to at least be running. Even though aside from the paint most the issues were minor, it would've helped catch my interest a bit more if those things were taken care of before seeing it.