What's the difference?

[Jeepsk8]

I met a guy camping last week that bought the exact same QS 6.0 off road edition that I did from the same RV center under the same circumstances (we both bought on a whim while en-route to go Jeeping) only he bought his a month before me. He was just so happening to stay at the same CG as me last week. We had a laugh at the dealership because of this guy doing the same as me only a month earlier, and he and I did the same laugh at the CG. We exchanged info and have been talking via text ever since in regards to Jeeps and the QS. An interesting thing, I decided to weigh the tongue of my camper this morning using the non-scientific method of a bathroom scale. The tongue really seems heavy to me and the scale confirmed it at 256 lbs! The only thing I have inside is a 10X10 popup awning, it does have a battery on the front as well. I texted him with my finding and through discussion realized the the sticker inside the door has different weights between mine and his. His sticker says the UVW is 780 lbs with a tongue weight of 140 lbs. mine says UVW of 840 with a tongue weight of 160 lbs. We both have A/C and a spare tire and everything else is literally exactly the same, including the color. They were even built within a month of each other. Why is there a 60 pound overall difference and a 20 pound tongue weight difference?