I finished my DR-MQ5 a while ago, and it was certainly worth all the hard work! Sounds amazing. I have a couple of things I'd like to mention about my build that people might find helpful.
First, the biggest issue I had was the power supply to power switch wires were inducing some nasty noise on the R/S channel high band. So what I opted to do was to put a 2 pole switch in there that shorted the connections on the LF bands, just like the switch was doing. Now I have the option of a shelf with variable Q or the bell. So sweet. So basically, the power switch is now "LF Bell shape?" On is Bell shape, Off is shelf shape. If you are interested in this and can't figure out how to do it yourself, I can be more specific. But if you take a look at how the rotary switch is wired, it should become pretty obvious that the thing that switches it to shelf mode is the 2nd pole shorting out everywhere except the step at Q 0.4
(I also partly did this mod because I was having a hard time finding a 2 pole rotary switch for the LF shape, and when I thought of this idea, I was like HECK YES! haha)
Second, the rotary switches I got for the front panel (the cheap chinese blue ones) had the shorter shafts and required me to drill out the front panel so that I could get enough of the shaft out to secure the knobs to. Make sure you get the switches with the longer shafts or be prepared to do some sketchy-feeling drilling on the front panel.
Third, since I'm in Canada, the 120v mains required a bigger fuse. I kept blowing the 315 mA fuses randomly. For a while I was troubleshooting until I realised I'm an electrician and I should know better! haha I think I got 500 mA fuses, and it's held since then.
I got the Hairball JE-990 opamps because they are supposedly cleaner than the API based offerings. I do like colour, but since this is my main mastering EQ, I wanted to make sure it suited everything thrown into it. I was considering coming up with some kind of 6 pole relay or 6 pole switch contraption to switch between DOA's haha but I'm not sure how much of a difference it would make to be worth it. I'm just happy my unit is up and running and reliable right now.
If anyone is interested, I can post some sound files. I haven't made any yet, but I can if there's interest.
Let me know if you have any questions. I should have posted sooner after making it, but I've been insanely busy mastering records with this incredible EQ. Hopefully I haven't forgotten too much..