Take an inexpensive, highly informative trip to a truck stop. Ideally with the RV loaded as for a trip. Have one of your crew drive the Taurus and pull both onto the CAT truck scale. Ideally the Taurus pilot gets out of the car and into the RV before the attendant triggers the scale. Only then will you know what the Taurus actually weighs and what the RV weighs. From that you can do GVWR and GCWR calculations, adjust tire pressures on the RV, and know what the Taurus weighs. All for $10.
Some of us have gone to qualified welding/fabrication/hitch shops and had reinforcing done. Sometimes the issue is that the 3500-lb hitch can be replaced with a 5000-lb hitch that spreads its mounting bolt load over a bigger footprint on the chassis rails.