The 55 will do things that no other plane will do.  Roy’s explanation is not th
ebest,- just play aroubd and you will get the big picture.  Just adjust the 2
fences to contain either side of the piece of molding you are working on, then
slide the center section back and forth to the right location, put in the right
blade at the right depth with the right support, and run that section.  Then
move it over and run the next section.

If all you want to do is run edge rabbets, then a Stanley 78 (better a Record
778 because of the 2 fence supports) will suffice, as well as a simple skewed-
blade woody.

If you want general small rabetting duty, try a Stanley 50 - much lighter, and
easy to set up and use

The 55 is a curiosity, IMHO

Ed Minch