Legs
The legs on the original kit are actually pretty good. The lower leg is fine as is (aside from the usual required joint replacement), and the upper leg is pretty good too, though a little scrawny. There are also some cosmetic problems with the knees.

Knees
The first thing I wanted to attend to was the pointy knee parts. They looked pretty soft, not very menacing, as a pointy knee should. In comparison with the huge curvy shoulder design on the Gaz-R/L, it just wouldn't do. So I built up the point with epoxy putty (the quick setting kind you find at hardware stores), first molding the basic shape by hand, then sanding it to a sharp point. The sides of the knee section (basically a cap for the lower leg) were also built out and reshaped using epoxy putty, giving them a more curved shape. I temporarily put the knee on the lower leg when applying the putty to the sides, to ensure a tight fit.

The vent/jet opening in the front of the knee is basically just a hole in the original model, and also needed work. I carved a "negative" of a beveled shape to fill it with, and glued the same arch shaped piece of plastic I used to make the chest vents on the end, then glued the negative on the end of a stick. The I filled the knee opening with Bondo polyester putty, pressed in the negative while the putty was still soft, then pulled it out after the Bondo set. This yielded a much better looking vent, which matched the chest vents in shape and style. You can see the negative part and resulting opening in the second picture at right.

In the process of bulking up the sides of the knee, I covered up the circular cutaways on either side, so they needed to be replaced. In my usual fashion, I decided to do this by pushing a negative into soft polyester putty. I ground away a rough recess with my dremel, filled it with Bondo, and pressed in the butt end of a hobby knife which had the right diameter. After the putty cured, I sanded it smooth, then glued in a Kotobukiya round mold for the raised circle in the center (not show in the picture).

To the bottom left you can see the new knee compared with the original. I only made one of these, since both knees are the same. I just made a cast of the modified part for the other knee.

Toe
The Gaz-R/L updates the original Galbaldy design with a pointy toe to compliment the rest of the design (good stuff!). This was simple enough to make out of sheet plastic, though I had to give it a couple of tries to get the shape right. I scribed a border on the bottom of the toe to match the kit sole detail. Again I only needed to make one, since both feet are basically the same.