Heck where do we start ?
I've never weighted rig? Pretty basic concept if your towing. You have great advice on how to do it now.
Next I would ask what PSI are you running with? Next would be are these drive wheels OEM and over 7 years old?
Not trying to pick but some of this stuff is really basic items we should all be aware of in being a responsible camper.
Looking forward to your scale numbers though :)
CAT allows two scale runs one without RV, one with RV. Plenty of parking usually for the trailer for temporary use.
Next lesson, each wheel weights :W
Good Luck and safe travels