SO. This is fabulous, for starts, and to assist as best i can with the helmet - engraving it first would be easier! but you'd need good drawing skills and instincts to be able to predict how the plastic will form once heated, because you may get the HUD diagram perfect, but then you form it and all of a sudden you realise its warped out of place. I'd advise using a carving tool to hand-etch the detail in, if you have a steady hand, because that at least means you can place the HUD where you want in the visor once it's been made to your eye level. (try not to shatter the acrylic, it can be a little temperamental, believe me)
But, to be fair, i don't advise a HUD at all, you want want it there all the time, and even if you don't light it, it'll be very distracting and out of place. But, otherwise, you are doing wonderful things and i wish you the best of all luck!