Yamaha only has Yue Ying, Mars, Ling Ying and Xunying, and there has never been a Skyhawk. Moreover, Yamaha's scooters are all produced in Zhuzhou, Hunan Province except Fuxi, which is produced in Taizhou, Jiangsu Province. The "Zhejiang Hongzhou Motorcycle Co., Ltd." (that is, Zhejiang Lingben Motorcycle) you mentioned has nothing to do with Yamaha, and its engine is not Yamaha's. Don't be fooled, but if it is 65433. It may also come from Yamaha Linhai. The key depends on whether there is a Yamaha logo on the engine, but even if there is this logo, it cannot be guaranteed to be 100% Linya's product. If it is a 50 or 125 or 150 engine, it certainly has nothing to do with Lin Ya.
Inquired from official website, Ling Ben, the scooter named "Tianying" has a displacement of 125, so it should not be the engine of Linhai Yamaha.