Iver Johnson famously used a "word-code" for some serializations based on their home city, Fitchburg, MA. : F=1, I=2, T=3, C=4, H=5, B=6, U=7, R=8, G=9. : A serial of "BHFI" translates to 6521. Locating the Serial Number
His method was brutal and beautiful:
Finding a definitive serial number database for Iver Johnson revolvers can be tricky because the company's factory records were destroyed in a fire. However, firearms historians have meticulously reconstructed these records based on physical features and surviving catalogs. Iver Johnson Revolver Serial Number Database BEST
These are the most reliable, though incomplete, resources: Iver Johnson famously used a "word-code" for some