What you have is kind of similar, but the holes in the sides and the location of the little hole in the top throws it off. (you probably saw an AGA "megaflow" plumbing kit and that's where the big holes on the sides came from. I don't know why they do that??) A properly set up duroso runs on a parital siphion, meaning it's a siphion but allows a little air into the mix which slows the flow down and keeps it from flushing. Those big holes in the sides completely throw the design off. Also the little air hole won't work well where it's placed in your set up.
A duroso should have a T on top of the stand pipe, with one open end pointing straight up and covered with a cap, and the center of the T connecting to an elbow that points down. The only vent hole should be on the top of the cap that is sticking up in the air. Basically you build it like this and drill a tiny vent hole and try running it, if it flushes (runs quite for a little while as the water level rises in the overflow, then makes a flushing noise as the water level drops back down, then repeat) it needs a the hole drilled out slightly larger (or much smaller if you drilled it way too big)
Google "duroso standpipe" and look at the many pics that will come up.