Paul,
I just purchased a used Becker Europa (mono) radio for my 230SL... It fits perfectly, and works great... all in one unit, no separate amp. However, it appears that my dash opening has been hacked on a bit by PO to install his Sony unit with the neon lights, so I can't absolutely confirm if this unit will fit without mod. I believe it is a standard DIN opening. If you measure your opening, I can check the spare mounting blank I have and advise you
Phil
230SL, 59 Jag MK IX, 65 Stingray Roadster, 89 Carrera Cabriolet