Ok, I am going to do *one* batch of renames, because it really bugs me, and I think people will find it legitimately confusing (I certainly do, and I've been starting at this code forever).
IconI -> IconItem
(InvItem + InvI) -> InventoryItem (the two classes get combined)
Inv -> InventoryBase
And then there will be some file renames to go along with it. I've tested this with DOSBox and ScummVM and there don't seem to be any issues.
IconI.sc becomes IconItem.sc
InvI.sc becomes InventoryItem.sc contains class InventoryItem
ScrollableInventory.sc contains InventoryBase and SCrollableInventory
InvItem.sc becomes Inventory.sc and contains your actual inventory items, as well as the instance of ScrollableInventory.