Concerning the embossing...maybe you could look for an old Dodge tailgate or something similar (or any other brand, maybe Ford)...then buff the DODGE lettering off and apply vinyl CHRYSLER lettering on top.
I don't know...maybe something like this from a '63:
Or this:
This one looks good too:
Ohhh...wait...here's exactly what I had in mind when I did mine in Photoshop:
After some welding and body filling, I'm sure you can achieve something really cool by yourself.
