The Helvetica, Times, Symbol and Courier included with the LaserWriter
printers mentioned don't have numbers; they are available only with ATM.
ATM users are probably the only ones who would ever want a PostScript
version of the font, since ATM uses the PostScript font to create the
on-screen representation.
Here are the font library numbers for the others:
Font Number Font
----------- ----
1 Palatino
2 ITC Bookman
3 ITC Zapf Chancery
ITC Zapf Dingbats
4 ITC Avant Garde Gothic
5 New Century Schoolbook
None of the font libraries has Helvetica Narrow.