L/L 37027 may be one suitable choice to renumber 37043 to, apart from perhaps the riveted roof, not sure if both are single or double riveted ? and just how noticeable this would be anyway....
L/L 37026 also, but it had a Black roof, unsure if it was light Grey earlier ? same applies 're the roof rivets.
L/L 37012 another possible choice, it had a light Grey roof to start with but was changed to Black later. same applies 're the roof rivets.
HTH
Perhaps A/S could list which locos had single or double riveted rooves ?