That being said, one flaw that I often find with this approach is that the game itself is consistently moving more and more to a frozen state. We have a set date in place for which we strive to make this shard more and more like...every update and patch getting this server closer to the target date of Nov 99. While that is a very good thing to have; having a goal in place to model this server after, it does however alter game play in a way that didn't actually exist during the era.
That is, during the era things weren't slowing down, each update getting closer and closer to a finished project, but instead the game was ever changing with new items being introduced, changes in skills and templates, new areas to explore, etc. And while many a veteran here will admit that this was what eventually led to the downfall of UO, it did keep the game refreshing, new, and exciting...always the chance for a mechanic to change or something new to be introduced.
Now then, enough forward and to the suggestion!
As I said above, during the era things were always changing, which kept the game from growing stale, keeping people's interest perked and the like, which is something that I think should be done here through changes to our current spawns. As I understand (and please correct me if I'm wrong here), spawns changed throughout the era and differed a bit from shard to shard. I've heard mention before of how on one server, a certain spawn may have a number of creatures while on another shard they were lacking. If this is the case, then era accuracy can't be exactly replicated through spawns, but instead the commonalities between the servers during the era should be how we model ours here.
This is purely for the sake of example, as it would be up to the staff here to decide how this could be carried out, but say the deceit lich room was changed one night and the number of lich lords was increased to say 3-4 spawning at a time. The lich room would still be the lich room (I'm not suggesting a different mob or anything custom of course) but suddenly it'd be crawling with activity. You'd see all sorts of pvmers trying to farm what now offers great loot, which then encourages pks to start hunting there, then perhaps the anti's come out, knowing that this is now the hotspot for pvp, etc etc.
Now then say after a few weeks, perhaps a month, the spawn reverted to it's original state. A few days later, someone catches word that a number of ogre lords (I believe this existed on some servers during the era) our now spawning on the island in lower Despise. Suddenly bards are making their way to Despise, competing for the spawn, pks follow, etc (imagine Despise being a hotspot!

Anyway, I think I've painted the picture well enough. The idea would be to keep the spawns ever changing with small changes done here and there, though always reverting back to an original state thus to keep players interested in trying new areas to hunt, keep pks looking in different areas for farmers, and the like. Furthermore, if this were to be something that was done unannounced, it would keep players guessing as to when and where the next change would be. Players would continually be patrolling dungeons, revisiting once abandoned areas, always checking out the spawns to see if and how they've changed.
Hope I explained it well, but the idea is to keep the game changing, exciting, and freshen things up for pvmers (thus stimulating dungeon pvp) all in a way that wouldn't compromise the shard's accuracy and would better recreate the era's excitement by always introducing new content.
Please discuss!