Trying to Help -
Here is a STEP file from the Autodesk Inventor 2012 KoP that you should be able to use. I know that Phil Dollan is working on getting the parts added as STEP files for select parts as there have been many requests for them.
This is stored in my Autodesk Cloud Documents file and I made it public for you to download.
https://documents.cloud.autodesk.com...s?hash=xXgUzPY
Hopefully this will work for you and your team!
Kim Campbell-Djuric
Autodesk, Inc.