Here's the completed garden bench / cart / scooter. It's stained now. I added four-inch, easily lockable casters for safety. It has a heavy duty pull rope. I added a cushion.
When the rope is not in use, it's easily tucked into the side opening. So i's not a tripping hazard.
I think it needed the back for sturdiness. I'm glad I cut openings to let light in and lighten the weight a tad.
Next to the old bench. Compared to that, this one is slightly taller, for my height; wider and longer for lower center of gravity and more sturdy. With the casters, I can scoot around on it, rather that getting up whenever I want to move a little.
So far I'm pretty happy with my new garden bench / cart / scooter. I think it's safer than the old seat, which was threatening to collapse when I sat on it. It's more comfortable for me, and more useful.
Except for the casters and the pad, all of the materials were upcycle / re-purpose / lying around in the woodshed or garage.
Update, my own review of my own cart!
This cart is far more convenient, comfortable, and useful compared to the tubular steel garden stool. There is just no comparison. It's in a different league altogether. I like it a lot!
Two improvements are needed. First, with the casters, it has a tendency to roll all over the place while being pulled. Sometimes it tips over. An axle with wagon wheels might not do that. I thought a rigid pull handle might be better. I ordered one on Amazon in June, but it has yet to be delivered. Shortening the pull rope by about half, helped about 90%. With so much less laxity, it doesn't get to roll sideways nearly as much. Much better, but not perfect yet.
The second change, those side pieces around the top are too thin, and break too easily. I need to find wood strips closer to 1/2 inch thick. Maybe a winter project.