Only the latter addresses customization of guns, and I've done a fair amount of that, plus fixing a couple of issues, plus of course all my cleaning of them, at

Only the latter addresses customization of guns, and I've done a fair amount of that, plus fixing a couple of issues, plus of course all my cleaning of them, at home. Or assembling your own, in the US AR-15 pattern rifles are pretty much the ultimate examples of both.