In file emacs-lisp-intro.texi downloaded from:
https://www.gnu.org/software/emacs/manual/texi/eintr.texi.tar.gz

1st bug was in function at line 20014, (defun print-Y-axis
I see it is fixed now with defun added at line 21463.

2nd bug is in function at line 21597, (defun print-X-axis-numbered-line
Fix is to insert additional line at line 21609:
(number-to-string horizontal-step)

Not all functions labeled "final" are actually final in this chapter.
Some have improved versions later in the text.
Functions in eintr-graph.el.gz were all copied from info version of manual while reading in Emacs.
Adding them as another page is just a suggestion. Fixing 2 bugs should be enough, I think.