Amelia
When you say: "Google is now looking for all those old Landlords pages under Smartloan." Do you mean in GWT you are seeing broken links reported?
After marking those URLs ask "fixed" in GWT, do they come back again as broken links a week or so later?
Are there any references to the smartloan site from the landlord site that are not supposed to be there?
Did you do a "Change of Address" in GWT or just request to block certain URLs? If you did a Change of Address, you might want to check to see if that is still in your GWT settings and remove it.
Otherwise, I imagine after a few weeks, the GWT will just clear up naturally by itself. It probably is not an issue to be concerned about.
Scott O.