Nice!
I'm on my second HF shop stool after the first one finally died. I had replaced the casters on it, rewelded the top and bottom of the post and the second time I welded on the top of the post, the adjustment mechanism gave up and wouldn't stay extended. It was bad trying to sit on it when it collapses. So the new one was purchased on a recent trip south and sports the casters off the old one which were way more sturdy than the ones supplied with it. So far, so good, but they are a little tippy if not careful.