What a wonderful association copy: Oman's own set of his history, or at least some volumes of it! That was a great find. I doubt that there is any connection with Ward though: he saw some of Oman's library for sale and bought what he could afford, but if his set of Oman is in Southampton I would imagine that that was not one he got from the sale.
I do like tracing the successive owners of an individual volume - usually they are completely obscure, but even then there is a nice sense of an interest shared across the generations and - sometimes - across the centuries. It will be interesting to see if the rise of e-books diminishes or actually increases this interest in the history of individual copies of books.