So today my neighbor (finally) popped the hood, jumped the battery, and got the car running. After removing the hardtop, he took it for a spin. While the hood was open I had a chance to walk down there; the car is in fact a 280SL, the M110 clearly visible. Still, it has all the Euro and AMG parts, and is a stickshift. Now, about that gargantuan 560SEL sitting a block down the street....