No, I wasn't. I took a tour through the forum and discovered what I was doing wrong: Configure, SET statements, commit, save and exit.
In the dozens of examples I looked at on the 'net, not one had the full script.
Thanks for your patience. I'm still having a problem with the second Set coming back "The specified configuration node is not valid". Do you know if the tftp server in FreePBX requires its own IP address? I've tried to find info on that but it's thin.