Not too sure on the brand. I would give the pump and body a good cleaning with some water and distilled vinegar. Make sure the Venturi is clear as well. After you do this and get it running you will adjust the water level in the skimmer with the red knob on the side. How deep is the water level the skimmer will be sitting in?
That's why I asked. In sump skimmers usually have an optimal water depth. Once you figure out what brand it is it should be easy to find. For now you can build a cheap eggcrate stand for it. I would shoot for about a 7 inch running depth and adjust from there if necessary