The most up-to-date assembly manual can be found here: http://spotswoodcomputercases.com/wp/?page_id=9137
Attach one post to an end of a short side beam, by sliding the head of the bolt into the top groove of the beam. Note how the bolt is tightened by inserting the wrench through the wrench access hole.
Insert 3 hex M3 nuts into the top groove of the short side beam.
Attach the second post to the beam.
Using 2x M3x20mm bolts (and a washer) attach the middle beam to the posts (note how the holes in the middle beam cannot be seen in the photo, below):
Using M3x20mm bolts (and a washer) attach the back long beam to the post & beam sub-assemblies (via the hex nuts inserted above). Note: Attach the long beams with the holes for the standoffs visible from the top) and press the beam against the sides of the posts.
Attach the front and middle beams.
The spacing of the middle support beam is 73mm:
Insert four hex nuts into the side of the back motherboard support beam.
Attach four black plastic PSU tabs to the frame via a M3x8 bolt and washer.
Using a M3x35mm bolt, washers, and a hex nut attach one side of a riser support beam to the frame.
[INSERT PIC OF ATTACHING THE BEAM TO THE FRAME]
Slide 16x hex nuts into the top slot of the riser support beam.
Finish attaching the riser support beam via another set of M3x35mm bolt, washers, and a hex nut.
Repeat the procedure to attach the second riser support beam.
Load 8 M4 nuts into the top groove of the GPU support beam and start 2 M3x14 bolts with washers and square nuts.
Attach the GPU beam to the back posts by sliding the square nuts into the inside groves of the side posts.
[INSERT PIC OF ATTACHING THE GPU SUPPORT BEAM]
Using M3x20m bolts, loosely attach the 8 motherboard spacers to the tray (finish tightening the standoffs after the motherboard is attached).
USB risers are attached to the support beams via M3x8mm bolts.
The PSUs are attached using #6-32 5/16-inch long bolts and washers. Note the third attachment point via a small 90-degree angle bracket.
GPUs are attached to the tray via M4x6mm Phillips-head bolts
Optional HD/SSD beams
The optional HD/SSD beams are attached to the tray with a M3x6mm bolt and nut.
Stacking connectors (threaded dowels) are threaded into the top of the bottom tray’s posts. The top tray is attached to the dowels with M3x8mm bolts and square nuts. Note how the bolt goes through the access hole on the side of the beam, pressing against the threaded dowel.