Here is the description of the Marlborough from the Historic England Listing. It mentions that the pub was built around 1900 and that the Marlborough appears to have been built on the site of a former building, shown on the Ordnance Survey Map of 1890.
Kelly’s Directory may suggest the building could have been the Postal Money Order Office and Savings Bank.
List entry 1393553. Grade II Listed Building: Marlborough Public House . May include summary, reasons for designation and history.
historicengland.org.uk