Special Purpose Plane?

by Don Knibbs
(Bramshott, Hampshire, England)

Can anyone help identify what this plane would or could have been used for, please? I came across it in a toolbox that belonged to my cousin who trained as a cabinet maker in the early 1940's. My first thought was that it would be for smoothing spokes or spindles, but the angle of the blade seems to be totally wrong for that. Also, the wear seems to be on the bottom edge of the plane, indicating it was used in the upright position.
There's no manufacturer's name other than THOs IBBOTSON on the blade, and some parts of it indicate that it may have been home made for some special purpose he had in mind.