The term "Straight Plow Beam" is self-explanatory. Instead of curving upwards, the beam juts out horizontally from the handles of the plow. Attached to the plow beam are the coulter and the hitch (or hake). Dr. Edward Maris identified fifteen different varieties that have a straight plow beam. The description of the shield as being "narrow" is a bit subjective, since the widths vary from variety to variety. Walter Breen classified the reverses as Small Shield, Large Shield, and Borderless Shield, which adds further to the confusion. PCGS lumps them all together into this type.
We know of eight Mint State examples of this type, though there are probably more in major collections that we have not included. The finest certified example is the PCGS MS65BN from the Bareford and Naftzger Collections. Looking at the illustration above, the coin appears to be glossy brown with traces of original red in the protecteced areas.