Well, the buildings that are auto-placed are the vector ones, which really look alot like the catalog ones. You could then go and replace some with the catalog ones, as well as also add to the placed vector one to make buildings look identical to the catalog ones. It really is a quite versatile program. Unfortunaley the reverse is not true, you cannot add to the symbol catalog buildings easily. It CAN be done, but requires an advanced knowledge of the software.