Image courtesy of James T.Robson
Too bad this one's not in the watch database :(
Bobbee pointed out the difference in the end of the vertical bezel engravings. Note the little engraved "hips" jutting slightly out on the horizontal bezel in the ad vs the straight vertical bezel engravings in the subject watch. Thinking the subject watch may be something other than the Spencer based on this.
One tick for Not Confirmed as now ID'ed.