I collect planes made by George Miller (working from 1890 - 1914) and when I saw this one for sale I snapped it up. It has an ebony infill and the rare 'rhino horn' protrusion, which is undamaged. This was the first time I've seen this feature in the flesh.
Like all Miller planes it has a nice tight mouth and is very heavy, weighing in at 1700 gr (almost 4lb).
The rhino horn can be used for a wider front grip......
....but I think it is more likely to help it to be used one handed.