Your photo is not showing up.I getI agree with Dennis -- good, clear, well lighted, close-up details of the loco and cab (and tender) are critical if you want advice like that. Videos are fun, but they're the wrong approach if you want someone to study details.
I guess my next question would be, "how do you want to improve it?". It you're trying for realism, nothing beats a good reference photo (see below). I have two initial comments: the cab is way too short. It needs to be several scale feet longer, and the tender needs to be closer to the loco (use a drawbar instead of a coupler), and you need to eliminate the front platform: the poor lout of a fireman needs to be able to shovel coal from the tender into the firebox without dodging obstacles.
Still, nice try for a first attempt.
Here is a reference photo for you, a Porter 0-6-0T. I know there are a lot of guys in the way, and the angle isn't great, but this one we cosmetically restored (in our "initial Unveiling" photo, with most of the volunteers who did the work).
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