Yes Scott, it is.
From what I read in the book, Hay-Budden made a change in 1908 in the way they manufactured the anvil top. This anvil appears to have been made right about that time. The serial number shows 1907 but the top is of the type made in or after 1908. Solid steel top as in the advertisement. So its somewhere about that date.
I think from the sizes Chris added above, this anvil is 200 plus lbs. It has had some arc welding done at the waist sometime in the past, probably where the wrought iron base and the steel top half joins. Nothing is missing and it has not been mistreated so that makes me think who ever had it new the make/value of this anvil and used it but took good care of it.