Chuck & Lynn:
Some 1958 18 footers had bathrooms and others did not. I
suspect the majority did not. If you trailer had a
bathroom, there should be signs in the floor where the
plumbing was.
Your trailer has the clues to show you the original layout.
You have to become an ASI and mentally reconstruct your
trailer's layout. Begin underneath looking for holes in the
belly pan where pipes and drains connected to appliances
directly above. Look at the floor for matching holes. Look
at the floor and walls for holes that held partitions,
furniture, fixtures, appliances and overhead bins. Look at
the roof for vent locations. By 1958, closets generally
did not span windows, so imagine a closet or other interior
tall furniture (stack of drawers) where the solid wall was
and a gaucho, table or low cabinet underneath the windows.
I don't have any 1958 literature showing layouts, but 1957
and 1959 layouts should be similar, so study them for
clues. In a metaphysical sense, the answer lies within your
trailer.
Fred Coldwell
VAC Archive Historian