Thanks, Bango. Unfortunately the part I am missing isn't listed on the part diagrams. It must be considered apart of the 503 89 82-01 part shown above. However, it doesn't look like anything is broken on mine and the threaded portion fell out so I can't imagine this is the first time this has...
Anyone out there have a 55 Rancher who can take a close up photo of the mount that the air filter screws into? I seem to have lost the insert/bolt somehow and can't find any information on a replacement anywhere. Seems like an easy part to fall out/loose but I haven't been able to find anyone...