Sorry, I didn't mean to mislead you, but that is not my build - it's a build by the member named 'Revvy'. Unfortunately, the picture doesn't make it obvious as to what the gang box might be stuffed into, if anything at all.
I see lots of member who simply stop at the gang box and call it good. My friend built one the same and stopped with the blue gang box as the outside. If I come across any ideas I'll post them here.
Edit: You can try PMing Revvy and asking if he put it in anything.