Here we go, pictures of the A300W with the 25mm fan and mods required for 10TB of storage. The mods may look difficult, but they weren't, nor were they time consuming to make. Enjoy.
The only visible modification is on the very bottom of the back of the motherboard tray, where a 1/4" section is removed. One can see the top side of the hard drives and the Velcro straps peeking out from the hollowed out section. The section removed is part of the base support, so only the center section is removed, while the edges remain in place for support. It's an ugly hack, but it's hidden in the back. The rest of the mods are completely hidden inside.
1drv.ms
This shot shows where the four flattened metal hoops were, they looked like cable management tie down loops. They were locating/lockdown receivers for the motherboard tray/case interface, but they were in the way.
1drv.ms
Here are the sections of the underside of the motherboard tray that needed to be modified. The drive standoffs were ground completely away, becoming horseshoe shaped openings.
1drv.ms
The left side bulkhead was removed entirely. The right side bulkhead only had enough material removed to allow the 15mm drives enough room to be mounted, hence the hollowed out ugly hack in the first picture of the set. The center bulkhead retains only the vertical component that is perpendicular to the motherboard tray, all components parallel to the motherboard tray are ground away leaving just a skinny wall between the drives.
1drv.ms
Here is the modified drive mounting
1drv.ms
1drv.ms
Compared to stock drive mounting
1drv.ms
And here is the complete assembly ready to insert into the case.
1drv.ms
*****A few notes to keep in mind. This is a very tight fit, but it does fit. Sliding the motherboard tray into the case goes pretty easily, but removing it was not easy. I actually had to flip the Velcro straps over at one point because the fuzzy side was binding and catching on the case. So, since the motherboard tray is sliding into the case on the Velcro straps, I recommend greasing those rails *BEFORE* you insert it because it is difficult to remove later.*****