First i hope your wife and daughter are fine !
About your thighs, they look perfect, they're rightly fitted to you and that's cool to see!!
For the Ammo knee belt, the length of the ends depends of the bottom of your right thigh. Just wrap it around (you can but don't bother too much aligning the thigh's front cover strip with the middle ammo box, the most important is the rivets placement) and then mark the length required on both sides to reach the back of the ridge.
Both rivets go through the upper corner of the knee belt wings to the bottom ridge of the thigh. Then you can glue the front to avoid shifting if you want. Rivets are painted white.
And if the ammo knee belt makes a 45° angle with the thigh it doesn't matter, it just happens sometimes. Like the one on the right of the picture below:
And 2,5mm for the TD strips might be too thick. I fear they would break before bending as much as necessary.
Good to see you're back on track though!