Duplicate assembly removal

Dupes, an old AutoCAD script looked for and removed coincident lines and circles, worked likke a charm. I find some scripts here (won't run in MAX 2013) but they seem focused on individual faces. After translating a file (.stl format) from Inventor to MAX, I found as many as 13 copies of some of the assemblies coincident. Taking them out was a bear of a time waster, and I was never sure I got them all. Now I have another file, same translation method, 4.5 million faces, over 4500 objects, I am sure there are some duplicates in here. Has anyone come up with a script to delete this garbage?