Do not underestimate a previous owner taking 'souvenirs' for their new trailer...or even their home. I've experienced the loss of good tv's being replaced with junk. Missing dash unit for backup camera...but left the camera. Just to name a couple.
You just might have had the perfect mount for their new bedroom tv...and they kept it.
Experience is what you get when you don't get what you want.
"We'll be friends until we're old and senile,....then we'll be new friends."