Wildman Hardpouch XXS (GK1) has a mounting system designed to be used on the handlebar of a bike - I didn't like that and I wanted it to be mounted on the top tube of my bike anyway.
You might need to file down a little the wedge that locks the pouch.
The top frame tube of my bike is about 42mm x 32mm, clips fit quite tight with the pads from an old innertube. They are somewhat adjusted for brake and derailleurs lines that run on top of my bike's frame.
The author hasn't provided the model origin yet.