Nice Albert Bagley gold combo. It is engraved on the extension barrel “Patented Jan. 1, 1850”. The green carnelian capstone is perfect with no chips. A replacement nib is needed. This design is a very clear predecessor to the “Mabie’s Patent” design (extending barrel). It is not marked Bagley but the patent date matches the Bagley patent date.
"Patented Jan. 1, 1850"