After researching several years I am beginning to believe that assembly letters were used on the M219/220's and that maybe the "Utility" sets (two barrels and two forearms) used numbers. I just received what I believe to be a "Utility" gun with the assembly number of "52". I have another with "333". A friend has one with the number "214". If you have a "utility" set will you please share with me the assembly letters/numbers? I will really appreciate this information.
