There's nothing wrong with that lathe/mill for aluminium as long as you're gentle with it (at least for the final cuts). Its a little harder to make by hand what Jonathan made by CNC (I suspect) but not impossible with some care. Like all things planning is key, understanding the order of processes etc. The engineering itself is relatively easy. What I find it best to do is draw it myself to help visualise the process. I know there are people that can look at a CAD drawing and machine it straight off but I find if I draw it in Sketchup the same way I would make it, i.e. start with a block and then remove bits, it helps visualise how.