But before you start salivating, understand that the majority of the ones to be found average about -20 Let's have a look at its Type study (Yes Virginia, there is a Type study on it :-) Well actually most used the No 110 Type study because they shared the same DNA but the No 120 never had the shoe buckle lever cap, nor the tapered body, having come after the No 110.
So you have to skip a few Type numbers to re-align them in proper order and of course they are some caveats...
It shows the characteristics of the first models but the actual patent is for the cutter adjustment that was never used on a production plane.
It was an offshoot of their popular No 110 which does not have a blade advance mechanism.
As Ralph discovered, its achilles heel is in the fragile blade advance mechanism. The small serrations on the movable lever are easily stripped if you try to adjust it without slacking off the lever cap pressure first.
Late in 1887 the star was eliminated from the lever cap The ubiquitous No 110 would continued to be manufactured to this day, it basically has kept the same shape/form since Type 5B except that the material and finish have changed thru the years.
At one point the modern version now used a cheesy stamped sheet metal adjuster screw versus a cast iron one.
The shoe buckle cap in the first design was very prone to damages, and abandoned early, but the smooth caps are also easily damaged. (think a star like on the US flag) That was as a nod to the country 100 anniversary.
Front knob receiver boss is raised about 1/2 in from the bottom of the casting Early style front knob is Applewood and slip inside a cast socket.
S - Or knob may be Fruitwood and have a tall slender appearance. The recessed neck is shorter stand only 5/16 in above the bottom. 1-7/32 in high J - Trade mark on cutter is small Type J.
All characteristics of Type 5A except: Stanley and No 110 now cast in raised letters and numbers on the bed in front of the mouth J - Trade mark on cutter is wider Type J.
Early example have steel wood screw projecting out of a cast iron cylinder raised above the plane bottom Z - Front knob is Rosewood. The center of the recessed neck is 11/32 in above the bottom. TYPE 4B No 110 Late 1879 to 1880 All characteristics of Type 4A except: D - Raised lug at heel of plane T - The short partial cross rib between the cutter supports is omitted. This change made it impractical to use the same body for both the No 110 and 120 O - The number 157 is cast into the bed at the heel.