If anyone is interested, you can get it playable using
these simple instructions. (Thanks Joe Leonard)
Then downloaded
this patch (thanks Morgrom) and unzip. Highlight all of these files EXCEPT the RenderEffects folder* and drag them into your Everquest folder replacing/overwriting them.
*There are 2 folders called MPL and SPL inside the Render Effects folder. Open them up and
manually replace/overwrite each of their contents.
(For some reason if the old MPL and SPL folders are deleted, even for a second, you get the no walls/ground/sky issue (like
so) since there is a dependency with other MPL/SPL files.)
May your quest be ever so good.