I work at a fab/machine shop(Georgia Metalcraft) in the NW corner of Ga., just south of Chattanooga. We regularly do work for Atl. area customers, this sounds like the kind of job we regularly do. If you like you could fax a copy of your prints to (706) 820-9642, or e-mail them to gametalcraftATcomcastDOTcom. I will double check that e-mail addy to make sure it's right, haven't used it in a while. 100 3x3x1.5 Alum. boxes wouldn't weigh that much to ship or we might even deliver it in person, depending on the circumstances.
I'm not in Atlanta and don't know of a shop that can do it but are you locked in to that size? If you can go a little larger BUD Industries makes a ton of standard boxes in different styles that might work and I'm sure it would be quite a bit cheaper.
I don't know if they sell direct but lots of electronic suppliers carry their products.
Best Regards, Keith Marshall firstname.lastname@example.org
"Even if you are on the right track, you'll get run over if you just sit there." - Will Rogers (1879-1935).