Inthebeech,
Brownells' Acraglas or the newer Acraglas Gel is the way to go, you can get black, white, brown or green dyes to color for stock color matching.
Brownells' also has a newer option Steel Bed, which is Epoxy with stainless steel added.
Then there is Devcon Epoxy Metals.
All sold by Brownells.
I still use Acraglas the original.