Another question.....
I am also looking at doing a maintenance scene diorama, and have looked at scratch building an engine hoist, but have also found a beautiful hoist made by Extratech: The full title is: Portal Crane - Airfield Maintenance1/48 B48007. It is available at Squadron, and it is an insane price, $86.00.
It looks like a bit too much for me to take on from scratch...for now at least. I have found a "jib" crane at track48.com. It is made by Gaso.line, and designed to fit to either a Panther or Tiger tank the product code is: HLX48230. I am curious, could that crane be modified to fit on the back of an Opel Truck? If not any suggestions? I have had people tell me that you really can't go wrong scratch building certain items, such as engine hoists, as a lot of stuff was put together on the fly in order to get the work done.