Key is not brass. Made of some type of medal alloy / steel. Marked I&M for the Illinois & Midland railroad has light to moderate wear. Basically a class one railroad serving the state of Illinois, serving Peoria, Springfield and Taylorville. They were primary a coal hauling railroad. In 1996 they were bought by the parent railroad Genesee & Wyoming. Since being from Illinois a difficult key to find. I have only come across two of these. A nice little gem to add for the collection. JF
