If you try to run the WOD scripts without the custom verdata files, its quite possible that POL simply won't start (with the "No graphic defined for objtype XXXX" error.) I didn't test that, though, so it may be able to get past that anyway.
Assuming that it does work, the biggest problem is likely that there are several items (and getting to be more all the time) that simply won't be visible to players. I recently changed to advanced alchemy potions to use some new stackable graphics that I added. If you don't have the right client data files, they'll simply be invisible to your players (though you can fix them by changing the graphics defined in the alchemy itemdesc.cfg file. Still, there's going to be more and more of them in the future, so that's little more than a short-term solution.)
Probably the biggest problem with adding items like I did is that they don't work with UO3D (at least not until someone figures out the UO3D file format.) You're pretty much stuck with UO2d. Considering how much the 3d client sucks, though, thats probably not much of a problem
Assuming you can get past the stuff above, the easiest way to make them available is to take the WoD player files which are available to download and rename them to something unique to your shard (its not polite to overwrite files other shards may need
) You have to make them the same number of letters as the original file, so for WoD, verdata.mul becomes wodverd.mul. You could just replace the wod with some abbreviation for your own shard. Once you do that, you then edit the UO client to look for the modified files instead of the original. To do that, you need a text editor that can work with hex files. Just do a search for 'verdata.mul' and replace it with your 'xxxverd.mul'.
The modified verdata files should work just fine with any modified map that you may have made. YOu can also use them as a base to add any extra graphics you may want to: just specify them as the base verdata.mul in whatever program you're using to modify the file. I've been using mulbuilder (
http://mulbuilder.hozyxon.net/) myself, though there are quite a few other tools.
*needs to make a permanent write-up for drocket.net*