That Trumpeter riveting tool usually sells for under a fiver, but there’s classic Amazon markup there. I’ll try the dressmaking tool tip though.
Re camouflage, I also used paper masks on my Tamiya Spitfire Mk1, it turned out really very well. I also use the tried and trusted Blu-Tack technique for marking out camouflage patterns, all you do is to paint the base camouflage colour in the lightest shade (either dark earth or grey) then bend lengths of Blu-Tack to an approximate shape and attach, before painting the dark green.
Project Lightning is coming along okay, everything has been sanded and rescribed, but late Lightnings were finished in a satin grey shade, which looks terrible if you try and pre-post shade. I’m keeping any shading to a very subtle level and once painted, I’ll give it a gloss coat, a pin wash and a coat of satin varnish.