Lefever is one of those rare makes which has almost as many exceptions to the rule as those which follow the rule. As a rule the later the gun the more the engraving which is reversed from most makes which tend to cut cost by getting simpler as they go to save money.
Jon;
If you look at catalogs of the era showing factory suggested list price you will see the reason for this. Competition was fierce & for a good period of time most companies were reducing prices. List price per grade on a Lefever remained unchanged throughout their life. Instead of lowering the price to meet competition, they up-graded the engraving etc & then at intervals added another grade at the bottom. Very early catalogs show the E as the bottom grade, then the F was added, then G & later the H & finally the I/DS.
