entire sole of the plane is also heavily cambered:
> https://groups.io/g/oldtools/photo/268441/3308618?p=Created%2C%2C%2C20%2C2%2C0
%2C0
Someone just had a need for that shape. For whatever reason.

When I was doing my little staircase I needed one, so I just grabbed a 
handy jack and cut it and patched the mouth. Easy peasey

http://users.snowcrest.net/kitty/sgrandstaff/images/homeplanes/gutterplane.jpg

see the stair rail?

http://users.snowcrest.net/kitty/sgrandstaff/images/house/stair1.jpg

yours scott

-- 
*******************************
    Scott Grandstaff
    Box 409 Happy Camp, Ca  96039
    scottg@s...
    http://www.snowcrest.net/kitty/sgrandstaff/
    http://www.snowcrest.net/kitty/hpages/index.html