I Had been asking yourself exactly the same issue. Lower amp TIG welding may be The solution to only welding the roll marks. What is the perpose of copper? The "C" over the barrel would indicate a chrome chamber only barrel. But AFAIK, Colt marked the "C" up close to https://brookspqomh.ktwiki.com/1075082/the_single_best_strategy_to_use_for_gold_cup_trophy_colt_45