In Europe in the early 90s there were several AMG (and Brabus, and others) tuned versions of then current models.

For example, when the 300E was released (with the M103 engine) AMG and Brabus produced a 3.2 version (I have owned a Brabus 3.2 W126 S-class, converted from 300SE). When Merc released the 24v (M104) engine, AMG and Brabus produced 3.4, then 3.6 versions of this engine.

I've recently been contacted regarding an 1991 AMG E34 estate (wagon to my US friends!) This was converted by AMG via Mercedes from a 300TE-24, suggesting a sales and engineering collaboration between the two companies in 1991.

For the record, I've also owned W123 estates (OK, wagons!) that were extensively modified by AMG.

Graham