The lowest grade was the Quality F and the Quality E had some engraving, finer checkering and had Fine Damascus barrels. The highest grade was the Quality AA and there are only a couple known and one of which I have the serial number to.
Finding a hammer is going to be tough but I would keep looking at eBay for one as they do show up there at times. That style hammer would be the Type 1 and was used until 1896 around serial number 545xx,
If you would be so kind as to mention the gauge and barrel length I would appreciate it for my records, thanks.