How can I find an old paper when the usual methods fail?
In the future, your university librarians are MADE for this!  Don't feel ashamed to ask -- there are librarians more into archiving and cataloging, and some more into education and service. 

Give as much information as you currently have, and they'll find it for you AND/OR show you how to find it yourself in the future (if it's accessible via a resource like some of those mentioned above.)