Making your own door panels?

[Orange '71 GMC]

Was looking at this this weekend, and stumbled across a little discovery.
I know/knew that the original door panels (talking about a '71 here) had a little bit of a raise in it around the edges, then also a little more in the center on the metal style. (I have '69 GMC panels).

I cut a template out of some 1/4" plywood to start working with, and noticed that I would have to have this lip around the edge, or have a gap. It seems that the arm rest mount or something hold the center of the panel from fitting flush against the door around the edges.

My only dillemma is, I am going to make my panels out of polished stainless hopefully, so I don't have the luxury of covering up any mistakes, or ANYTHING with fabric. I may (if the budget withstands) skin them with some etched HIGH polished stainless, but we shall see.

So, what have those that have made their own panels done to get the edge to fit flush? How big of a gap do I need to expect to fill?

Thanks all!