There probably is an HDD. You can see two SATA cables coming from the board just behind the lower GPU - they will go down into the lower section which is where the HDD are mounted in the TJ07
would it also be possible to solder the 24pin to the back of the mobo?
i also think its not a 10 because nothing is perfect IMO. but that is definitely pretty **** close so id say 9.9.
a while ago i had been through this entire thread and i know that there are other cases that i think are in that 9.x range also but i really dont remember them lol, although i do remember a rig from Jfenwick(?) i think with 4 gpus; really clean too.