Hi my window is TBT with this hardware. At 9:20, this is what my window also has, but I've noticed it doesn't have a tight seal just after half way down the window and looks like it could do with another roller cam on the hardware (opposite side to the handle). Any idea how I could fix this? I believe you sell the side I'm needing that has 2 of the latch things rather than just the singular one. Is it easy to do myself?