This is a National N5 Plane.
I've put it up for sale because I've never seen one before. Made in Canada, possibly some time between the the wars, although it looks earlier to me. It's an odd tool - some bits of it I like - the handles are good, and I like the look and feel of it, and the profile of the plane body too. But some of the casting lets it down. The blade looks ok though.
It has a brass or bronze depth adjustor fork - not seen one of those before, and it has a sweet little adjusting wheel too. It does have a lateral adjuster, but no screw for moving the frog back and forward.
I'm quite fond of it really, which might be just as well as it could easily be one of those tools that follows me to the grave.
We'll see!