its been converted from euro to usa headlight spec. I assume you have a MPH speedometer , too.
My '78 350 slc 4 spd is velour interior/man windows/singlemirror. the 350slc's didnt come with a lot of options.
you can email the MBUSA classic center and they can get the original build sheet for your car, if you dont already have it.
you can get the headlights on us or german ebay.