Yes. The tiara worn in the 3rd picture, with the pearl dog-collar and necklaces is definitely the Surrey Tiara. It is from a sitting that was taken just after Queen Victoria's death (hence she is wearing black for mourning), whilst she was Duchess of Cornwall.
This picture, or one from the same angle and sitting is featured in Roberts and definitely calls this the Surrey Tiara, cross referencing it from a picture of the Surrey Tiara from Queen Mary's Photographic Inventory.
There is no doubt that this is the Surrey Tiara, worn on the base of the Girls of Great Britain and Ireland Tiara. (This also indicates that the base is much more adaptable than first thought and can be detached from one piece, and attached to another easily).
--Previous Message-- : What I meant was - in the third (not 2nd, : sorry!) photo, the tiara which appears to be : on the base of the "Girls" tiara : isn't the Surrey one. It looks like : something else entirely. This is the photo : with the pear dog collar now worn by the : Duchess of Gloucester. : : --Previous Message-- : The surrey tiara is actually the necklace. : : : :