There is a big bookstore where I live called Powells. They have a very cool rare book room. Here is their website.
www.powells.com
I did a search in used and rare for poe and these were the results
http://www.powells.com/search/DTSear...n=RareBookRoom
Not sure if there is anything of interest there for you. If not you can call them. They are very good about tracking things down for customers.