Guess the object

I called in at F's house while I was in town. He was very pleased to have purchased this object from a charity shop.

Any guesses as to what it is? I wouldn't have known without being told.

Well Done Mr P and John for getting it right. It's a carpenter's grooving plane from the 19th century and is made of mahogany, steel and brass. F is going to clean it all up so it's all smart and shiny,