Hopefully the experts here can verify whether this is a Type 5 (1885-1888) or 6 (1888-1892) based on the markings shown below.
The lateral adjusting lever has two (not 3) patent dates: Feb 18 76 and Oct 21 84 which should mean Type 5.
The lateral adjusting lever has two (not 3) patent dates: Feb 18 76 and Oct 21 84 which should mean Type 5.