The same is true of creature parts and enchantment formula; any that the relevant person had before taking the battle tower will be available to your servants afterwards.
If you go into the enchantment, potion or creature creation functions, any formula or parts left in your inventory should be duplicates, and can be sold.
That is neat!
It also opens for the interesting possibility that all my lost creature parts - the merchants in Broken Valley village keep nicking them from my inventory whenever I make a trade! - will reappear when I get my tower.
But I doubt it. As you've already told me, in reply to one of my former posts, you too believe this one to be a bug. If so, it is one I can live with. I have tempered my hoarding instincts concerning rotten body parts.
