I should have looked at Chuqli's post and photo before responding.  It does look like his 1900 Rider deck does indeed have the smooth hills and taller grass.  But what is does not have is the longer side on one of the sides of the "paper clip" coming out from the center.  So it appears that that error was corrected in the 1890s, but the smooth hills were retained.  Because the Rider back is so common, I did not collect any decks unless they were the oldest vintages, 1887 - 1890.  I will try to do more homework re the timing of the hills change.
Steve

Hi Matt - I have S58 and S59 - both in great shape.
Steve