Excellent condition for its age (175 years!) with absolutely no pitting and has original machine marks on the blade. Mahogany (rosewood?) handle has the usual toolbox wear. Early Sheffield partnership. Very uncommon makers.
"By 1852, William was a general merchant and manufacturer in Eyre Street with Joseph Denton and Joseph Burdekin....In 1863, Corsan’s partnership with Denton and Burdekin was dissolved." https://hawleysheffieldknives.com/n-fulldetails.php?val=d&kel=2028