Out with the carb... What the hell it this?

After pulling out the carb, I gave it a clean, and found that its some kind of Chinese carb with Deng Ling written on the side. It also has an odd rubber bung where the air filter should be. Im going to buy a 19/19 dell'orto carb from ebay, and bolt on a larger manifold so that I get a power boost. Im also considering a 135cc engine upgrade, but that depends on the state of my cylinder...