they have been renumbered eg 64 Strand st went to 77 c. 1875 (see www.manxnotebook.com/gazateer/inns/do_qy.htm) - I think there was another renumbering around turn of 19th c.
Most, if not all, of Strand st was shops (though with living accomodation above) - these are generally easier to track - do you have any names