I finally took the plunge and ordered all the parts to finally build a SEQ. I’ve also decided to design my own enclosure. I was able to track down the mounting hole dimensions for all of the PCB’s besides the Quad IIc_MIDI PCB. Could someone out there help me out? Thanks in advance. 
Hi if you are using 4 IIC boards then the mounting hole spacing is 1.85" x 1.42" for each board. If you are going to use the quad IIC board from Smash TV, well I’m sure he can help you out.
Good luck