The Dungeon of Signs blog points out some very consistence ideas about the over arching fairy tale of the adventure material; "Palace of the Silver Princess has a story, of the B series B3 is the first module to try to tell a complex story akin to a fantasy epic or fairytale. The story is confused and muddy, but at its core there is something quaint and fun about the tale of the Silver Princess’ kingdom cursed by a wedding gift from the dwarfs. The whole idea of the castle being magically transformed to evil, and attracting an evil patriarch who seeks to finish transforming the peaceful valley kingdom into a dark hellscape full of carnivorous roses is also fairly fun. It’s just a question of how to do it. Palace takes some brute force approaches of locking the party into the castle with no chance of escape (which gives new players the idea they are supposed to camp inside the thing), then it creates a situation to remove the curse with three solutions that aren't really clear, and provides explicit clue giving green fairies to nudge the party in the right direction. This is not a fun way to run a D&D game. What if the players decide they area a pack of blackguards intent on plunder? That the valley of Haven turns into an outpost of some evil ruby eyed demon is not necessarily a loss condition for a party of wandering plunderers, and really it provides a better source of a campaign then Princess Argenta back on her throne handing out boons. "
Looking over the Jean Wells version of B3 pdf hosted over the vaults of Pandius website & we're left with two very different & yet similar products. The fairy tale or is it nightmare? The nightmare of a chaos god whose been dreaming about the kingdom of Haven from the beginning. Could it be that Princess Argenta called it much earlier in the events of B3? Events went from bad to worse as the magick of Haven's nightmare enveloped it.
The Dungeons & Dragons Review Guide Maintained by Mark Bertenshaw has some excellent notes on using B3 Palace of the Silver Princess with Mystara.
Further we have even more ideas for running a campaign with Mystara especially with the
Mystara Module and Placement by Andrew Theisen article. Mystara has always played its share when comes to the B/X modules. Greyhawk & Mystara have been linked as two very different aspects of Dungeons & Dragons. This doesn't mean they have little use in the world of the OSR. Quite the opposite in fact.
Mystara connects to the dimension of Nightmares & through it the demi plane of Shadows. B3 Palace of the Silver Princess is a fractured fairy tale waiting to happen. And perhaps one of a number of battle grounds that the adventurers might find themselves in when the trap of Haven is sprung on them.