A brief explanation of Grades, I just found a Hamilton watch grade 936 good or bad?

The 936 is first rate, that was Hamilton's first railroad watch. 936's are under-appreciated in the current market, so they represent an opportunity to acquire worthwhile early Hamiltons at reasonable prices

Really, all Hamiltons after their earliest watches were first rate in terms of quality and jeweling. Not sure they ever made a watch after about 1900 that wasn't at least jeweled to the center wheel (17 jewels).