It appears that the H-D Holding companies are mostly located in the heavily concentrated manufacturing industry areas in Jiangsu Province the backyard of Shanghai.
1. Jiangsu H-D Environmental Technology: located Rudong county, Nantong city, Jiangsu province.
2. Shanghai SHDBM New Material: headquartered in Shanghai Pudong district.
3. Jiangsu Fortune Oil Products: located in Shanghai Jinshan district, with manufacturing plant in Nantong.
4. Jiangsu Shengyuan Gas Power: located at Qidong county, Nantong district, Jiangsu province.
5. I can not determine which heavy-duty truck manufacturer is in H-D holding. But all three possibilities are in Jiangsu province: Xuzhou, Jinjiang, and Nanjing. Considering there is a manufacturing industry chain, there could be many parts and assembly line companies scattered in Jiangsu province around Shanghai.