I don't think the manufactures weight includes options. These can add up to several hundred pounds.
The mfg. tag says my Heartland Grand Canyon weighs about 13,200 lbs but I weighed in on CAT scales and it was close to 16K. Could that be right? There is no way I had around 2,500 lbs extra weight.
Don't trust the stickers in my opinion. It could easily be wrong.
Now that I have gotten a new sticker my GVWR of 16,000lb and empty weight of 12,xxxlbs. Still not sure why the empty weight would have changed just from correcting the GVWR.