A really nice example of the very rare Stanley 4 1/2 H.
In lovely condition, and pretty certain 100% original. Low knob, excellent handle with light and dark wood, small brass adjustment wheel, SW blade - generally all round this is a very tidy plane.
The lever cap has what possibly might be original moulding faults, or possibly pitting. I could replace this but to be honest I think it would be a big error to move away from the original.