I just realized why these instructions weren't making sense... I had updated WPTouch in the past, and had somehow gotten a version which was incorrectly numbered 1.9.41 instead of what should obviously have been 18.104.22.168 since the current version is 22.214.171.124. When the version_compare function evaluated the version I had installed, it looked like it was much newer than the actual newest version, so I was never prompted to upgrade to 126.96.36.199. (The version I had did not list the user agents currently handled by WPTouch, so I couldn't follow these instructions.) I deleted WPTouch (which actually kept my settings) and reinstalled the newest version, and I have the list of user agents now.
I don't know how the WPTouch developers want to handle the "version sinkhole" that happened, but I suppose as soon as they go to a 2.x branch, the sinkhole will be avoided.
Note to everyone who is having the problem described here, but can't find the place from which to copy the user-agents, see if there is an update available and if you are using version "1.9.41", you need to manually upgrade.