I recently finished a PSU for an M49 with one of my PSU chassis.
Due to the square shape of the M49 PSU pcb I placed it on the far right on the dividing panel to give enough room for the bigger choke necessary for this build.
I realized that it gets packed on the IEC connector side and I might look for a better position in a future revision of the chassis.
For all other mics the pcbs are placed more towards the center of the chassis so it's not that much of a problem.
Anyway I thought since the space to the right of the M49 PSU pcb is so crowded I decided to do a little 10 step guide to show the order of steps which will make the build as simple as possible.
Before step one of this guide you should look for the tiny hole on that side of the chassis where the XLR and binder connectors go in. It's located approx. 2cm from the top edge. Enlarged this hole to fit the pattern switch necessary for M49 builds. Then mount all other connectors (XLR, Binder, IEC, fuse)
Then step 1 of my little guide here - place the mounting studs for the pcbs first:

Step 2 is mounting the power transformer and step 3 is mounting the choke. Also visible in the pic you see the mounting holes for the 20VAC transformer

So step 4: mounting the 20VAC transformer:

Step 5 is preparing the shaft of the voltage regulation pot with a metal saw so you can use a screw driver later to turn it:

When you're done mount it to the dedicated holder:

From the outside it should look kinda like this:

Step 7 is to feed through all wires from the power transformers and connect them to the IEC, fuse holder and power switch.
Step 8: connecting the power wires to the pcb, soldering the choke wires and the wires leading to the adjustment pot to the pcb,
then mount the pcb (you might also connect a wire to 0V for case grounding already)
Step 9: mounting the pilot lamp holder (the mounting studs I used to mount the pcbs were rather long, so I decided to use some shrinking tube around the lamp holder to avoid contact between the lamp holder and the stud - see in the next pics)
Step 10 is wiring it all up



And this is what it looks like from the other side:

I hope this will help you a little

If you build different mics with this chassis please feel free to post some pics here so we all can learn from it!
Martin