i think you should use these files
K750_R1CA021_MAIN_CHINA_CL_RED36
K750_R1CA021_FS_CHINESE_RED36
K750c_CDA102338_7_R18A_Generic_Trade_China
but i am not sure about the cust pack
Thanks for your help. I will try other drivers before flash it, since I don't understand how to flash it.