it looks like an improved pattern mitre plane like Spiers, and Matheison, except the front bun does not neither does the brass knurled knut on the lever cap, also unusual rounded front steel to the plane. is it for sale?
J Howerth Co made irons but I've never seen a infill plane made by them.I agree it does resemble the Spiers improved miter in some ways but not completely.I would guess it was made from parts bought from a couple different companies,even Norris sold parts to others for the money as did most of the known makers. I agree it's probably worth some money although not as much as it would have been if it had Spiers name on the lever cap still it's a nice miter plane and a great find. Len