Is this brake shoe legal ?

[Chamberpains]

You're correct about where the lettering is. That is the 1/4" mark for legality purposes. Yes, that is a perfectly normal design to a drum shoe. No, shoes don't wear evenly. I believe you're looking at the anchor side of the shoe. Which is the trailing end of the brake if you drive your vehicle primarily forward. The other side is the s-cam side, which makes contact with the drum 1st and wears out faster. So it should be thicker.