I did indeed have a Marshes & Shepard that I modified (one of my very first forrays...) into The Marshian.
I had also thought that shape to be a result of 150 years worth of strange honing (which is why I deemed the balde to be of little practical value, and thus was the frist to visit my Frankenstienian dremel laboratory...)
However, I too have now seen 2-3 other Marshes and Shappards with the same thumbnotch, and the same tapered blade shape.
Thanks so much for posting that info, as it has laid that quandry to rest once and for all. I owe Bill Ellis an apology!:ziplip:
I have since sold The Marshian, but it was a damn fine shaver! Really, super-smooth feel to that steel.