I tried converting art.mul and artidx.mul from client 7.0.75.35 and dropping them over a 7.0.7.1 (pre-UOP) client and it doesn't work. Strangely enough the new large empty plot *is* visible but the rest of the newer houses and most of the artwork is still missing. There must be something about the size of the new file that the older clients just don't like.
I tried to do this on an older version of ServUO and it almost worked but it ended up causing enough problems that I abandoned the idea and started over from scratch with a newer server core, ironically the one abandoned now which makes my current code obsolete even before I open it to the public!
Other changes happened around the time of the larger plots to allow the client to "see" a greater distance. Much of that happens on the server side though so you may be ok as-is. I had issues with pieces of the large houses & plots remaining after the house was dropped until totally re-starting the client. Whatever wasn't on-screen when the house was dropped was still there until restarting.
