there are some W110 parts can't be installed in your W111 220SEb, like bumpers(W110 and have single large ones while 220SEb have 1 large main bumpers and 1 small one on top and the length of it's sides is also different,USA models had overriders and different plate light positions on the rear bumpers as well),fenders and headlamps.

I remember this one guy that he purchased a new set of front bumpers for his 1962 190b (gasser), when the bumpers arrived, and installed, he noticed it's sides are longer and will rub the front tires when turning, he called me up and when I saw his bumpers, I told him that's for the 6-cylinder 220S sedan not for 190 you know 190s are short-nosed version of 220b/Sb/SEbs, after telling him that, he was furious and wants to take his money back.