100% google image search, as you said about the front end. It's a Carlsson C25, but it's not based on any Mercedes model. It just uses the R231 SL chassis. --- Post updated --- Guess this
Nope. It's something British => American and not known much. Raced originally as a Gr.C2/IMSA Lights car, converted to a IMSA WSC car in 1994. Here is the WSC variant. Althrough it had a make/model name originally, it was renamed to feature ONLY the name in 1994.