The placard by the drivers seat may give you some information on GCVWR ( total weight of coach and towed) and also GVWR ( total weight of coach only).
Now the hitch may only be rated for 5000lbs, or it may be higher.
The hitch may be changed to a higher rated one if you have the room with the GCVWR. I had a custom one built for my bus to handle my 24' enclosed trailer.
My loaded weights with trailer put me about 500 to 1000lbs under my GCVWR.
Hope this helps some