So, do you have two pieces for the sides that are 10 1/2 inches by 2 1/2 inches? And then you would need two pieces that are that are 15 inches by 2 1/2 inches for the top and bottom?
Are you saying that the longer ones are only 14 inches? or are both sets too short?
I'm just trying to understand so I might be able to help figure out what to do.