I took out my HP71 and it is silver. But, I also looked closely and think I know how the "trim" is applied.
It ain't trim. The face is brushed aluminum with the color and key functions silk-screened over. You don't want to apply new trim but new color.
I did post an idea (that never received a reply) for repair for older HP's which had trim applied around the raised perimeter. This may work for you repair.
Hobby stores sell a product used to simulate metal finish on plastic. The product, "Bare Metal Foil", is an adhesive backed, ultra-thin foil you can cut and apply to simulate a finish. It's inexpensive, so worth a try (although I have noticed some on this site are cheap skates - can I say that?)
Check out the product at www.bare-metal.com, a hobby store, or an issue of "Fine Scale Modeler" magazine (my source) or "Scale Auto Enthusiast." I can't say how tedious or durable this is but it's worth a try. You could even make the gold trim you want.
Joe
PS. If there is more to this reply, ignore it. I got up to find my 71 and returned to a blank screen.