I recently bought a well used NH 616 Disc Mower. I will be making all my own hay now and cutting about 50 acres. I'm trying to find a user manual but with no luck. I'm just trying to figure out the routine maintenance for the cutter. I know the oil needs to be changed but not sure where all the fill and drain plugs are. Plus where all the grease points are. Any help getting this cutter up and running would be a great help.