Concerning the leaded barrel, I doubt anyone nickle plates the inside of a barrel. Leading in the barrel is most often caused by the bullet not fitting properly, might need some forcing cone work, not really sure, but if the cast bullet fits the cylinder, forcing cone, and barrel properly, leading is usually not a big issue. So the diameter of the cast bullet comes into play, along with the sizes of what I mentioned above. To get a little bit of leading out I sometimes use Chor Boy solid copper pads. Cut off a little patch of that, wrap it around your cleaning brush, and it scrapes the lead out with one or two passes. Fast and easy. A little bit of leading here and there is something most us put up with, but you should not have big streaks of it going down the bore, something needs to be changed if it's that bad. Also, be sure what you think your looking at in the bore is lead.
If it fit's, and functions, and shoots to point of aim with fixed sights, thse are the things I look for, and it's not all that easy to find a fixed sighted gun that shoots to POA....which is one more thing ya half to fix if you get one that does not.
Good luck