Just look at my post... just about identical with my 560 SEL (but I'm betting that its the radiator). I bought a new Nissens radiator a little over a year ago and it LOOKS fine but when I reverse flushed it, I got little white particles coming out of it and although it doesn't run hot as quickly as it did, it still does because I probably didn't get enough of the crap out of the clogged radiator and it is still restricted enough to warrant the higher temps...
Did you feel your radiator for cool spots after you stopped your engine? I'd feel around the radiator (in the direction the fan blows) and would find that it would be cool on one side and while running my hand along the radiator, would get hot as hell itself to where I'd damn near burn myself. Check it and see if the same happens with yours. I've got a new Behr on the way now because my old radiator worked just fine (the neck's just shot so I don't want to chance it like the PO did). Before that I also changed the thermostat,coolant tank, cap, etc but just because the radiator's "new" doesn't mean it can't fail--just like thermostats. Good luck
1970 250C SOLD
1971 250C SOLD