This is discussed elsewhere on the site, but didn't notice that till after I did it. The cleaning blades were corroded and broken on one of my kettles and I thought I'd upgrade to a "high capacity ash catcher" while I was at it. I took a look at one of my kettles (which turns out to be an "ER") and saw the little slots for the ash catcher tabs, so I went ahead and ordered from Weber. But the one I did first is a "C" and doesn't have the tabs. So I went the hose clamp route but slightly differently than is described on the site.
Here's the underside of the kettle, note the lack of slots. (Also the rust, this kettle is pretty old and has been outside its whole life, wonder how many more years I can get out of it?)
Since the tabs don't fit facing out, I used a pair of pliers to reverse them, so they face in. Carefully! Once! That aluminum doesn't look that stong.
Now the mounting ring fits!
There wasn't quite enough clearance for the hose clamps so I cut little slots with tin snips.
Tightened up the hose clamps with a long screwdriver.
Done!
FWIW here's what the cleaning blades looked like to start
Grinder: brutal but effective
New blades installed. Seem to fit a bit tight? These are also the new, modern kind, with the slots instead of nut. Wonder if it will be easier to replace when it burns out in a couple years?