Okay you are using the Slackware tarball, right? Note that the Slackware current binary package is from Jul 21 2005, which means it's a Slackware-10.1 package compiled against xorg-6.8.2.
If you don#t know how to pick your way throught the code of the script, you can still update the source config files.
Just unpack the original archive, cd into the sources and run 'autoreconf -if' and then repack the sources and run the script.
Building and packaging WindowMaker is not usually as straightforward as most programs.
A lot of the patches and config stuff that I use come from the ALT/Sysiphus Linux distribution which is maintained by a long-time collaborator/contributor to WindowMaker project.
The package I uploaded has the history list and single-click already activated(the single-click option is in the Prefs Expert section).
The history list is activated simply changing this:
%a(Run,Type command to run
%A(Run,Type command to run
in the Prefs options for the 'Run...' desktop menu item.
But I install default menus and config files that set all that up by default.