Try looking on frame, road side tongue just below where the LP tanks sit. But on the frame. Not LP bracket. Sorry I my trailer isn't here or I could run out and give you an exact location. Good Luck!
Robin, your vin location was perfecto. After finding it, sister and bro-in-law discovered they had purchased a 17' liberty instead of a 16'! This was a total whim buy and if you are interested I will share their adventures. First one was hauling it down the mountains from Reno. Pat's comment: "oh dear".