I don't think you are grasping the issue - there is no code in the 1.0 gametype scripts to open the server info menus. So, setting a dvar - ui_motd - is not going to accomplish anything because there is nowhere to show what the cvar says (no menu open = empty space).
Oh, i thought he tried to use a 1.0 mod on a 1.3 server, which would open the menu but would not set the cvar.
"Does not work" is an error report for a bug between keyboard and chair.