The light grey one without the raised dot on the barrel is quite possibly a repro as all confirmed originals to our knowledge have the raised dot.
The darker grey with the slight raised dot could be original and a poor mould example. If you believe it might be painted try lightly scratching the surface of it to see if it reveals another colour underneath. Of course it's also possible it could be a repro too.
Certainly hang on to both in case other examples turn up. If you can provide individual pics of both these blasters showing both sides they go on the IG waiting list till we get more evidence.
Sorry can't help more than this for now, hopefully others can chime in.
thevintagetoyadvertiser.org 1970s and 80s vintage toy ads and other retro paperworks
imperialgunnery.com Vintage Star Wars action figure weapons and accessories guide