Managed to get a fair amount done the past couple of days; here's a run down.
Tray trimmed with the angle grinder, came up pretty well and pretty pleased with the result.
Had to come up with a method of mounting the tray and rear panel in the right place seeing as it is now far from a factory finish - the tray was easy as I just put in new pilot holes to the case and reattached with nyloc nuts in the original tray holes (countersinks gave a good flush fit).
The rear panel was abit more involved as it's from an entirely different case so I had an idea; I pulled the rear panel into position using an old sound card to guide it in to the tray properly with the motherboard screwed down; rather than screwing the rear panel in I applied some JB Weld on the seams and clamped it down over night; resulted in a rock solid bond that's spot on for the current and future expansion cards and will still allow the use of up to E-ATX on the tray.
Some neoprene cut down ensures a seamless fit and will help keep any dust out - far from a clean finish and not a conventional method to mount it up but it definitely works solidly.
SAS backplane is configured to look after the 3 Noctua PPC fans so cables are at a minimum and all work spot on - noise wise they're alittle loud spinning at 2000rpm but no way near as much as the 80mm and redundant PSU fans it came with. Airflow is substantial. Mounted 6 WD Red 5tb drives.
Remaining pieces:
- PSU side bracket to take weight off of the rear panel.
- need x2 more 5tb WD red drives for second array.
- mount CPU cooler.
- design small front panel cover where the disc drive and USB header used to sit.
- install OS and configure RAID arrays.