Paul, I remember a tool called a 'shoe'. The roll of paper mounted to a spindle on the top and there was a hopper that held a small amount of mud. I worked much like a caulking gun, squeezing the handle would produce a thin ribbon of mud under the paper. It was a two man job, one ran the shoe and the second guy worked the tape and excess.
I guess that it was not all that successful as I haven't seen one in over 30 yrs.