I think RayBee's on the ball here. I am now dimly recalling a light duty wide bucket for a 2910 that they usually show carrying wood chips or mulch. For someone who want to carry and move large volumes of lightweight material.
I'm changing my tune. I would not want that bucket instead of the 54" one. I, too, have welded reinforcements on the top edge of my 54" bucket as well as grab hooks. I do a lot more lifting, prying and shoving of heavy things with the bucket (stumps, rocks, logs, digging) than I do carrying large volumes of fluff. Good catch, RayBee.