This u-clip fits onto the metal backing under the armrest and screws (two of them) attach to it to hold the armrest in place.
Clip at armrest location - 15712350
If you have one, or more, of these you would not mind parting with I would like to buy them from you.
Clip at armrest location - 15712350
If you have one, or more, of these you would not mind parting with I would like to buy them from you.