I am not an expert on the history of these vehicles. I didn't get into Mercedes until quite recently. I am a former AMC (Rambler) convert. So, anyone more knowledgable, please feel free to correct this. Anyhow, I thought that the 129 Series cars from 1990 thru 1994 had bumpers and lower body trim color painted with a flat finish or sometimes a contrasting color (black). Your car looks to have all pieces painted in gloss. That's why I thought it was possibly a 95 or later. A 1991 SL500 would sell for about $15K US were I live from a private party; a few thousand more at a dealer with a short warrantee. So much depends on the condition and the previous maintenance. These cars require strick maintenance to give good service.

__________________
Resistance is Futile.