Stuart Nicolson Antiques has dated this piece to the 1800s.
Stamped on the underside.

They evolved from the well known firm of Mack, Williams and Gibton (1811-29) who were at 39 Stafford Street, Dublin and were appointed Upholsters & Cabinet Makers to his Majesty, His Excellency and Lord Lietenant and His Majesty's Board of Works in 1806.

They supplied for some of the most important public buildings in Ireland, including the Four Courts, the war Office, the Barracks Office, Dublin Castle, the Chapel Royal and the Treasury and Viceregal Lodge.

Simultaneously they were commissioned to produce furniture for many of the grandest Irish country houses such as Ballynegall, Co. Westmeath, Oakley Park, Co.Meath and Strokestown, Co. Roscommon.
See Knight of Glin, Dublin Directories and Trade Lables,

Furniture History, 1985 and A.Alexander, The Dublin Cabinet- Makers in the early 19th Century: Furnishing with Style, Irish Furniture, The Furniture History Society.
54 inches wide. 26 1/4 inches deep. 28 1/2 inches high
Stuart Nicolson Antiques has dated this piece to the 1800s.
Specialist in the care, conservation & restoration of fine period furniture.
You can view the stock and full dealer information on the Stuart Nicolson Antiques Profile Page