From the introduction of the Grade 1 hammerless guns in 1890 into the early 1900s the 12-gauge and smaller gauges were Quality PH with a list price of $65 and the 10-gauge was Quality NH with a list price of $70.
Here are the pages form the "Blue Ink" catalog (circa 1900) which the late Ed Muderlak had reproduced.
PH- and NH-Grades.jpg
By the catalog that introduces ejectors (circa 1901) it is just the Quality PH with a list price of $65 in all gauges but 8-gauge which is $105. I've never seen an 8-gauge Grade 1 hammerless with the watertable marked NH.