I am missing something that is at the core of the issue.
Here are the steps I just took this morning as I started from scratch.
Download the SKD
Extracted the .tar
Here 7zip asked me if I wanted to replace the "existing file"(odd because this is a new path). Yes, no, auto-rename. (I tried all 3 at different times to see if the following step worked any differently)
Found the tool/file ncc_att_hwid in the expected path
Downloaded the sysupgread.bin image
In the command prompt navigated to the path where the tool is and tried the command posted above.
It gives me the error 'ncc_att_hwid' is not recognized as an internal or external command,
operable program or batch file.
There has to be a problem with my process that is at the core of the issue its like I am using the wrong environment or something at the base of all.
You need the full path to ncc_att_hwid. For example /usr/home/***/Downloads/......
Secondly, it is a 32bit binary, If you're running a 64bit LInux machine you will need some 32bit libs. I don't do windows so I'm not sure what you would specifically need.
If that does not work post back. I installed to a TEW-810DR using u-boot, usb serial adapter, tftp server and the initramfs image - did not need to append the cameo signature. The Trendnet shares the some board/OpenWrt build as the D-Link DIR-810L so it should work for you.
There are some fixes in the latest kernel 5.4 build (NIC port numbering, and detection of the WAN port) which I'm running on my Trendnet TEW-810DR. I have not tried the recently committed DSA code.