Today I drilled new 1/2" holes in the outer ankles. The center of the holes is 0.5" from the tip of the ankle (and centered much better front-to-back than before).
It was a bit tricky to set up the drill press and legs to be at the right height, but I eventually got it, and was able to drill good holes.
Reversing the process from the other day, I used a C-clamp and some scrap wood to press the bronze reducers back into the ankle bolt holes. These reduce the holes from 1/2" to 3/8", for the 3/8" ankle bolts that will connect the feet to the ankles.
Next, I bolted the shoulder brackets back onto the legs, and set up the drill press to drill new 5/16" holes in the gas pipe. This is necessary because yesterday I trimmed the gas pipe by 3/16". Now the pipes overlap a bit differently, and new holes are required for the two 5/16" bolts that lock them together.
I decided to drill the new holes just outside of the old ones. Alignment looks good, the bolts appear to fit just right. I won't know if it's a complete success until I reassemble the droid and try driving it, though.
Finally, I'm embarrassed to say that the threads on my U-bolt for the gas pipe are pretty much trashed. So much so that I had to saw the old U-bolt off of the angle iron that it was attached to, since one of the nuts is completely stuck!
I think that the holes I drilled in the angle iron are ever so slightly too close together, so whenever I shoved the U-bolt through those holes, I was wearing down the threads. I will hack on the holes in the angle iron soon, to alleviate this problem. In the meantime, I luckily have a spare U-bolt I can use.
I hacked down the ends of the new U-bolt to allow a socket wrench to reach the nut once it is screwed down all the way.
I also started hacking in the grooves that are used for traction against the gas pipe. I still have a lot more of these to cut, I only had time for a few of these before it started getting late.