The early versions of the "Magnum" series drills had more red nylon and less aluminum parts. They also used 4.5 Amp motors. Later they did more aluminum, especially the gear case and upgraded to the 5.5 Amp motor. I have a 3/8" version 0-1200 RPM model 0224-1. As for the name plates saying 0234-1 but the box saying 0234-6 that's all for marketing. The -6 means the instructions come printed on English, French and Spanish. The actual tool is a 0234-1. They did make a special -75 version for the 75th Anniversary. They are collector's tools but were made to work hard too. The aluminum parts are done in high polish and they have a special plate with limited edition serial numbers on it. Sometime I'll try to post some pictures of one of them here. I got my first 0234 in the early 80s and remember the changes when I got my second one in 2005. The second one is in use now. The old timer finally wore out so it's in retirement here. NO way is it going into the dump.
By the way even now they have a 0244 which is the same as a 0234 but geared slower. I think but need to check that there is a keyless chuck model 0235 high speed 3/8" version still made. It runs too fast for me and the keyless chuck is a POC but is easy to replace.
NavyBuck, What is the first 4 or 5 digits of the serial number on your's? Actually if there is 532A or 532B you have one of the last really good ones. The new 532C = Too many Chinese parts inside. It's not a bad tool but I like more USA parts.
To everyone I hope you are lucky and have a MILWAUKEE keyed chuck made in Japan on your's. Those are really good chucks. Some have a more junked up chuck on them. The early ones used a true Jacobs industrial chuck which was really good quality but today is also big $$$.