Does anyone recall what other hosts besides Monty Hall played on ABC's 'Password'?

Gary Moore definitely.

It was a few years before Feud, but Richard Dawson. Although technically, he appeared on the "All-Stars" version, while hosting Masquerade Party.

Nobody went with the obvious, Betty White? Never mind, I did.

Going by what I have in my 71 TV Guides, Merv Griffin, Bill Cullen, Carl Reiner and Art Linkletter did the show that year (in addition to Monty). Arte Johnson and Betty White also appeared in 71, but before they had hosted a show. Jack Carter was on that year, if you count pilot hosts.

If I get some more time, I can check other years, unless someone else would like to take it from here.

Looking at this episode guide, these hosts (or hostesses) appeared during the ABC run:

Bill Cullen, Merv Griffin, Arte Johnson, Betty White, Carl Reiner, Dick Martin, Monty Hall, Art Linkletter, Soupy Sales, Ruta Lee, Rod Serling, Tom Kennedy, Gene Rayburn, Bert Convy, Dick Gautier, Larry Blyden, Vicki Lawrence, Richard Dawson, Nipsey Russell, Pat Harrington, Allen Ludden (when Monty Hall took over as host and once when Betty hosted as well), Don Galloway, Bobby Van, Arlene Francis and Elaine Joyce.

-Jason