Ronvella,
Good luck with your conversion. It sounds like you have the basic gun pretty well along in it's conversion. Now comes the fun part, regulation. That's where the hair pulling really begins. It's best just to do a little at a time so as not to get frustrated. I think your 303 will make a great light hunting gun. You never said, but how much does it weigh? I have done a 45-70 on a lightweight 12 gauge Laurona, and you are right about the cheap finish. Here is something that might help you out. The main thing that I found wrong with the Laurona was the lousy quality Nickle finish that they put on them. Brownells sells a Nickle remover that comes as a two part formula that you mix in equal parts and it really does work well. I had a man who wanted his double finished with a brown finish. Ya, I know, It isn't traditional, but that's what he wanted. So, I stripped the Larona's Nickle off and polished it up and browned it for him. He was tickled to death with it. He chases bears and mountain lions with his dog pack and didn't want any flash to his gun for fear that it would make the quarry bail out of the tree. It worked out well for both of us. You could also blue or caseharden it if the steel will take any color. I have not tried that yet.