OK, so I am building the knee panels and finished them. I went to install them and they don't fit. So I checked the plans. The inside dimensions of the MIP structure is 1515mm. The FMC width is 523mm. The knee panels are 500mm a piece. This adds up to 1523mm. Well the math doesn't add up. I am 8mm too long. Did I miss something? Need some help. Thanks in advance.