I am looking for some help with a Sima Rossi horizontal milling machine. It looks to be one of the older models with a serial number of 115. The photos on Tony's UK site show models show a turret type head. This model has a extending arm on a dovetail set up with a Tree MH4 vertical head. I am looking for a operation manual that explains how the drive system for the horizontal milling head works. It has a gear box on the top and bottom and I am not sure what the bottom gear box is for. I would appreciate some help with this.