You know, it's been a while since I've done any prototype building, but I am a mechanical engineer, and did quite a bit of this at one point, so I submit this to the group for consideration. I'm sure that many of you are already aware of these processes, so forgive me if these comments are obvious.

There is a process called stereolithography (STL) which creates a plastic part in "layers" using a laser hardening resin. The resultant part is brittle, but (depending upon the machine) can have a very good surface finish that requires little or no work. These models are used frequently for mock-ups, but they can also be used to create molds for plastic parts.

Plastic resins exist that can be used in a silicone mold that is created on the STL part. Molds can also be built from the STL positive that can be used in a vacuum molding process for short production runs in polyuretheane resins. The polyurethane can be prepared in any color. The resultant part is typically not useful for all applications, but for a fascia that doesn't carry any load, I don't see why it would be an issue at all. A polyurethane fascia would be just fine, it seems to me.

Compared to spending upwards of $15-30k for a "soft" tool to be used in a plastic injection molding machine, these approaches can be very economical for low run (under 100 units, typically) model building.

Finally, there are processes that allow STL masters to be used (destructively) for aluminum or steel casting, resulting in a metal part instead of a plastic part. Another alternative is to create a silicone mold from the STL model and use it to pour wax, which is then used in a lost wax casting process to create metal parts. Imagine: a brass fascia for your empeg!

Jim