Bob,
If you are looking to create the original look under the hood, as displayed by Ed Cave's example, you should note that the diamond pattern firewall pad is impossible to find. The "pebble" grain is the only thing that has been available for years. Maybe Millers, SLS or someone can tell you the manufacturing source and get one made without cutting out the section for the data plate (I find the patched up version annoying myself but there may not be any choice).
The three rubber bumpers are also different in appearance. I haven't replaced mine yet but I think the new ones have rounded edges versus the original squared off version.
I know these things are minor...I just happen to be an originality freak!
Best Regards,
J. P. Mose
1968 250SL
1987 560SL