Yeah I know that feeling, I had my helmet master done up for close to a year before I finally grew brave enough to call it good and permanently turn it into an expensive silicone mold.
With painting though, I say definitely just do it. It's never too hard to hit the eraser via some sandpaper and give it another shot if you really don't like it, and tbh you'll probably find it easier than you think.
And yeah rattlecans can be great, especially for just a trooping-level job. Just don't overspray till it's runny, and follow the recoat time instructions closely and you'll be fine. Airbrushes are mostly advantageous for their much wider color options, and much smoother spray surfacing, but they do take a bit more tinkering to use though, mostly in just thinning correctly and keeping the damn things from not clogging up. I'd recommend a single-action if you do, much simpler and better for large spray volumes like a whole helmet surface. Paasche H is a fantastic SA brush.
