@amoroso @masinter No, HELPSYS is not included with that version, nor are any other supplementary files.
However, I see some HELPSYS stuff among files from SUMEX-AIM, another big Interlisp site. There is a <HELPSYS> directory with each file being a chapter in a manual. And there is what could possibly be the HELPSYS code:
FILECREATED "17-APR-78 13:36:06" <NEWLISP>HELPSYS.;1
Does this seem helpful?