Yes there is a tool to do the swagging with. The late Carl Shoupe used to make them. I made mine using needle nose pliers and a drill press. Takes practice to get it right. Either here or Stuka stunt is posts on swagging. So far have had no problems even over doing the pull tests.
MBS Model Supply carries a swaging tool that looks to me like a commercial product.
They also carry sleeves that come in both black and silver (I think he packages them both into the same kit -- you'd have to ask him if you order).
When I swage, I color-code with the sleeves from MBS, and I cover with clear heat-shrink.
Or you can wrap with copper wire -- it's prettier. You can buy a 1/4 roll of #30 or #32 magnet wire, one each of some light color and some dark color, and your great-grandkids will still have copper wire for winding lines.