has_many :old_nodes, :class_name => 'OldWayNode', :foreign_key => [:way_id, :version]
has_many :old_tags, :class_name => 'OldWayTag', :foreign_key => [:way_id, :version]
has_many :old_nodes, :class_name => 'OldWayNode', :foreign_key => [:way_id, :version]
has_many :old_tags, :class_name => 'OldWayTag', :foreign_key => [:way_id, :version]