Quite a variety of responses! Interesting.
We'd need a picture of it to tell exactly what it is.
I've seen a number of long planes with narrower irons in the past, but almost all of them were user made.
OK. Here is a general picture.
I don't
think it is user made. It has a varnish/finish on it that is none too professional, and probably the sole has been replaced at some point, but it doesn't have the feel of something knocked up in a garden shed. It feels like a pretty run-of-the-mill cheaply made mass produced item, not particularly old, but I could be wrong.
There are a couple of "maker's marks" on the top of the plane but they are difficult to make out.
The iron has some numbers(?) on it but it is not possible to read them. The cap iron has a mark like this one:
(This image is from the internet. Mine is the same but not so readable.)
Probably a simple smoothing plane simalar in size and use of a later no5 plane.
A sharpen up of the blade and your good to go.
My Stanley No 5 is only 355mm long so the woodie is considerably longer. Indeed, my Anchor No 6 is only 455 mm so this is a fairly long plane.
Assuming it's an old solid-body plane with abutments for the wedge & a typical wedge with side projections & 'scooped out' centre, the narrow blade is likely to be a very poor fit.
The iron and the wedge don't seem to be such a bad fit to the body as you describe. Here are some photos:
Having looked at it a bit more, I think it is deceptive. The iron is 50mm wide but feels narrow. The iron in the other wooden plane I like is only 55mm wide but feels a lot more substantial.
The plane has obviously been used until quite recently. As I received it the iron was still sharp enough to cut paper.