I had one that went motley off colored. I tried to cold blue it but it didnt take well. After trying several types, the stuff from Brownells did best, tho it looked more like color case hardening than blue. A guy on the leverguns forum refinished one by carefully sanding/polishing off the iron plating, then cold blueing, it turned out pretty decent actually. It took the cold blue pretty well.
"Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt-