Hi,
I have been given some firmware files from JideTech which may assist. This link will expire in 1 week: 3516EV300-200521.bin and 1 more file
It contains these 2 files: 3516EV300-200521.bin and Hi3516EV200_200905_8M_LT.bin
The first one has a hash match to the original poster's root...