Its always nice to see some finished projects and it does encourage people to persevere with getting their machines running.I've never had to work with guitar components,but I have some experience with second operations on one or two different machines.They key was to use a suitable fixture at a known position and that probably won't be easy to do with Vcarve until you have an .stl file of the fixture.Presumably the files for the components were supplied in .step,.igs or .stl format.and if you can subtract this shape from a solid block in some other program,you should be able to generate a fixture with the mating surface for you parts.The easy way to make it work isn't to toil through the process of offsetting all the surfaces and trimming/joining them.Instead just lie to your tool library about the actual size of the ball end cutter you use.If for example you have a 6mm tool-tell the tool library its actually 5.8mm (best to give it a description that labels it a clearance cutting tool)o r so and the toolpath will have a bit of clearance for the machining cusps.