cannot disable paren matching

[Don Woods]

I am having a problem where paren matching is not working as desired,
and I am unable either to turn it off or to make it work correctly.

The specific case where I'm having trouble is in PostScript mode,
when also in Overwrite mode.  When I type a character that acts as a
close paren -- such as > or } -- the character is inserted instead of
overwriting the current char.  Emacs briefly highlights the matching
open paren, or reports a mismatch, as the case may be, but does NOT
remove the char I was intending to overwrite.

Since I don't especially need the paren highlighting in my current
editing, most of my attempts to work around this bug have involved
trying to disable the paren-matching behavior.  I have tried such
things as

(show-paren-mode 0)     ;; no noticeable change

(show-paren-mode nil)   ;; no longer shows matching open
                        ;; but still does not overwrite

(modify-syntax-entry ?> "w" ps-mode-syntax-table)
                        ;; > now highlights the char AFTER the matching <
                        ;; but still does not overwrite
(modify-syntax-entry ?< "w" ps-mode-syntax-table)
                        ;; when combined with previous, > goes back to
                        ;; showing matching <, but still does not overwrite

I know I've tinkered with other paren-related vars without success,
but no longer recall everything I tried.

My only successful workaround so far is to scrap postscript-mode and
use fundamental-mode.  I'm using overwrite-mode while editing a portion
of the PostScript file that is a block of "ascii art" data, so don't
really need postscript-mode there, but it's awkward when switching
between the data and code portions of the file.

Note: emacs-version is:
"GNU Emacs 22.1.1 (mac-apple-darwin)
 of 2016-04-22 on osx143.apple.com"

Suggestions appreciated!

        -- Don Woods