On pewter nose caps i do just as Dave suggested .
Here are some photos of a pewter nose cap I did on a rifle some time back .
I wont go into the actual pour becouse i do it very much like Ken posted
For things like wrist inlays , which I pour right to the stock , what I do is drill a few holes at an angle . Then drill a small connecting hole . In doing so the inlay locks down to the bed and becomes stronger .
Here is an example. On this inlay , I prepped the bed and then set the brass plate which was under cut . Then I drilled a few interlocking holes with a 1/8 drill bit . Made my pour and then filed it all back down . The inlay isn’t more then about a 1/16 of an inch deep