Ithaca Gun company offered custom engraving services from its in-house engraver, one of which was retained until about 1972, or through an outside contract engraver, who was usually William Mains. Many customers requested some degree of custom work and guns with various patterns turn up from time to time. Four standard engraving patterns offered to customers: Grade 1; Grade 2; Grade 3 and very elaborate $1,000 Grade pattern. Increasing production costs forced $1,000 Grade to become $2,000 Grade, $2,500 and finally $3,000 Grade over the years. NOTE: All factory engraved Model 37 guns are rare and require an expert appraiser to determine an accurate value.