Remix of kai's HardDriveHolder D7, which didn't fit in my DS1815+.
It is not that pretty, well, it was, as it came from kai, perhaps I will do some further improvements. But in this state it will work just fine. Appreciate to get some input from the community for the work tbd.
Made some minor improvements, front is now printable without further support, as I added a smoother structure, which was removed before, because of fitting issues.
Added a plate on the upper end to stick a small mirroring surface on to see the LED indicator placed above the hdd tray.