I hate to say that I told you so, but I told you so. How did I develop this physcic ability, easy cause if I was one of your local customers, I would ask you ifin you'uns might a build me one! As far as time goes, if you've never built one or something similar, I'd say that your rate of design and assembly are on par with most, especially since you have a real job without unlimited hours to invest!
Lastly I am a firm believer in the old measure twice and cut once theory, it doesn't matter if you measure 150 times like you said or 1500 times,like I would, it is empowering and allows you the confidence to move forward without second guessing. Very impressive, if I was local you would be forced to get a restraining order, due to me hanging around wanting to help turn bolts! Count your blessings, Matt