You can get part, service, and owner's manual reprints from Ken Cook.

Ken Cook, Manuals for 1956 RJE-18
Ken Cook, Manuals for 1957 RJE-19
Ken Cook, Manuals for 1957 RJEL-19
Ken Cook, Manuals for 1957 RDE-19
Ken Cook, Manuals for 1957 RDEL-19
Ken Cook, Manuals for 1958 RDE-19C
Ken Cook, Manuals for 1958 RDEL-19C