Rob, your work is beautiful. Not sure I can help with the set up, mine is probably more rudimentary than most. I set my area up to be comfortable for me. I use a drill press bottom cut off so that I can raise and lower my work any time I want. It just sits under my office table. (got the idea from these find folks) I have an adjustable chair so I can raise and lower it also. When I first started I just adjusted my table, drill press/vice, microscope, and seat to see what would be comfortable for a few hours at a time. Trial and error. I think that would apply to anyone, if you are comfortable you will spend the time to practice. Staying in one position as you know is hard enough. I have a large compressor I use in my garage that I piped into my basement and also a med. size CO2 aluminum tank I get filed once in a great while when my wife doesn't want to hear the compressor going off.
. Most of all, how you have been sitting and working for 47 years must work for you, use that and adjust the rest to fit your comfort zone. I am not a professional engraver like most of these artists are. Trying though. So their years of experience would be who you would want to listen to. I know my comfort zone with engraving and airbrushing, it is probably different than others. Good luck and you will absolutely love Steve's equipment.