Thanks for the kind comments.
Of course the buffalo came from a buffalo nickel. I used a jeweler's saw, needle files and a dremel to cut it out and shape it. Also, it had to be thinned to lay in the grip properly ... not the easiest thing since I didn't have a grinder; I did it with a flat file, holding it on my leg and rubbing the piece back & forth. Let me tell you, the metal in those old nickels is HARD. I broke several saw blades and it took a LONG time. Luckily, I used a good original coin, so the relief didn't need any additional "sculpting". Also, I'm right-handed, so I only did one ... on the side that would show when the gun is holstered.
Compared with the buffalo effort, the grip itself, inlaying and checkering, was a piece of cake. As I was removing wood for inlaying the buffalo, I kept the sawdust. My cut-out was a close fit, but I was able to use the dust, mixed with a little glue, to fill in the fine gaps (like between the legs).
I'm very happy with the result, but I'm not eager to do it again (well, maybe with a silver or gold coin).