Thanks for the additional info IanW. As you say, there is a bend in the blade now when it's screwed to the cap iron but fortunately it is minor and the assembly sits flush on the frog. I think I'm going to find a suitable #4 and widen the mouth a bit so I can use this blade and cap iron combo in it. The steel seems to be pretty good, not too onerous to sharpen by hand and doesn't seem to dull too quick.