This makes using the plow blades marginally easier, but also allows the use of virtually any symmetrical cutter such as hollows and rounds, beading, reeding and nosing blades.
This beautiful tool is our favorite plane in the collection.
The 41 was offered from 1872 to 1897, and was probably phased out in favor of the more versatile Stanley 45's.
The plow has very substantial 1/4 inch thick cutters which is a design feature that was probably inherited from wooden plow planes which had thick, tapered blades.
In a wooden plane, the taper on the blade helps to keep the iron tight against the wedge - backwards force on the iron serves to tighten it.
Hone the backs and flats of the blades on an oilstone or waterstone.
400 grit wet/dry sandpaper with sharpening oil does a really good job, too, especially if you finish off with 600 grit.
The skewed cutter on the fillister bottom makes cutting easier, and the fence, supported by two arms and running the length of the sole, makes the 41 less annoying to use than its closest rival in our shop, the Stanley 78 duplex plane.
There is a small spur knicker ahead of the blade on the edge of the fillister bottom for working across the grain, but it is so small that it is doubtful whether this was ever much use, as there is no room to re-sharpen or adjust it.
You'll find lots of times blades have been modified for a special project and may be left completely unusable.
Pitting from rust on the back of the blade may also make it useless - no matter how well you sharpen the pits will end up in the blade's cutting edge. on moulding blades and find that they work well without it, but if you're going to use one profile a lot (and especially if you insist on working a difficult piece of wood) you might try it.
I usually work over the beads with a very fine chainsaw file, drawing it along the face as I work.