Hope it's not bad form to post links to other forums, but here are two mower builds I happened to come across on a German forum. The one guy has a video of the Unimog mowing but he's made the video private. Use Google translate or Chrome viewer if you can't read German.
Unimog
http://www.das-baumaschinen-forum.de...=4549&pageNo=1
Tractor
http://www.das-baumaschinen-forum.de...&threadID=6174