http://www.hammondmfg.com/dwg_SBVer.htm
MXR has varying sizes of enclosure.. eg, the distortion box is not the same size as the phase 100.
The distortion is 1590B in the above link, phase 100 is the BB I think.
Those boxes at RS are bloody cheap, compared to buying from Small Bear Elec or other overseas suppliers. I'm gonna get a few of the 112x60x27. Almost the same dimensions as the 1590B's.