I do nickle plating of guns and fortunatly what goes on with electrical current can come off with electrical current. Do some research on reversing plating process and you can bring it right back to copper normally but being as you cannot reblue the copper you must remove it also. Some people just nickle plate over the bare metal as the copper is just more rust protection but it is a step that can be omitted if you are trying to do a cheap job. So if you have an original gun and knowing the plating really knocks the value as would a total reblue job I would opt for the lesser of the evils and reblue it. You will still reduce the value but if you go to sell it and are honest with the buyer about it being reblued which most will spot right away you may get a better price than a plated gun. I have reversed many 1911 45's that were plated including gold plated which goes right over the nickle. If you have a original trench gun I really envy you as I have looked for years and not found one yet that is truely original at any price. I would not mind but almost all have said the famous words I don't know much about it as this is how it was when I got it. Now anyone getting a real trench gun is going to know every square inch of it and I cannot beleive anyone would be that naive as to not know exactly what they have with that type of gun. OK Guys start the bashing ha ha.