the rubies jango isn't terrible actually. it's a little smaller than the accurate helmet, but it's surprisingly good once you replace the visor and give it a real paint job. as far as painting it up you can do it like any other helmet. sand it down nice and smooth (at least to 400 grit if you're not attempting much silver in your paint job, if you do want a shiny helmet then you'd better keep going with 800grit, 1000grit, and in some cases as far as 1500-2000grit sand paper), then prime it (i like rustoleum gray automotive primer) then sand that down with 800 grit (or whatever the highest grit sand paper you used), then start applying your colors. always remember, light coats. no sense in laying it on thick all at once because you'll just have to sand it down once it runs on you.
once you get it sanded and primered feel free to send me a pm if you'd like a few more techniques.
p.s. feel free to cut out the visor area, but don't install the new visor until the paintjob is done.