My thoughts about the OP question on doing decent work with shakey hands:
Gunsmithing requires a great deal of relatively costly tooling. And the lack of experience with a particular machine can lead to unneccesary / overpriced / unusable / inadaquate machines. I, as a model builder, would suggest a small, relatively inexpensive machine such as the convertable lathe (I can't remember the brand) with the capacity to be a mill. It would not be an "end all" device, rather an introduction to milling machines. Most such machines continue to be useful into the future for small work while the "normal" jobs are done on a full size machine that has been chosen with working foreknowledge. The tooling can often be used on a larger machine as well. Professionally, I was an electrician before electronics and engineering. I started out with machine work on a UniMat DB-200. I now have a couple of moderate sized machines, a 9X20 and a 12X36. Most of my UniMat sized tooling is still in occasional use.
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