I am a new member...I have a James Rogers folding knife that no one has been able to give me information about...Never seen a knife like this...It has the James Rogers mark VcrownP and his name and Sheffield...Bone handle with a piece of ivory attached to the bolster about the size of a thumb nail...This knife is in near mint condition...My grandmothers mother had this knife in a sewing kit for at least 100 years... The knife is 4 1/2 inches closed with a 2 3/4 inch blade..The ivory "thumb" is 1 inch long...Any help appreciated...