I really do not have the means to make a site like this, but I do have a great suggestion!
Instead of having a webmaster maintain a site like firstcadlibrary, have a site where anyone can just go on and upload their CAD parts similar to
www.putfile.com.
At the same time when they upload the file also have them include a description, a picture of the CAD file, multiple file types of the CAD drawing (if the up-loader is able too), and also allow them to choose the category the file should be uploaded to.
I would gladly help organize what the page should include and give some of my suggestions!