Well a couple years ago I was picking up the good old ShopSmith 10E(R) for anywhere from $50 to $150 rebuilding and selling them. I kept 2 of the oldest for myself; 10E Serial Number 12103 from early 1949 I use as my horizontal machine, primarily lathe. And 16061 from mid-1949 which will be used as my permanent drill press. I will be showing some of what I did to those here.
If you are lucky enough to have one of these great pieces of American history this Yahoo! Group is a great source of information, http://groups.yahoo.com/group/Shopsmith10ERusers/ They also manage a spreadsheet that has year manufacture by serial numbers.
If you are looking at restoring yours, here is another great site with a wealth of information: http://www.shopsmith.net/forums/showthread.htm?t=3503
If you need new parts here is Skips site http://www.mkctools.com/10erparts.htm
Here is a shot of the data plate on 12103, the horizontal machine.
And here are a few shots of what I had to start with: