I bought the Pro GO 76 slim for the Roland BK9.. it was close but no cigar, I sent it back and got the regular size.. Turned out to be a good move... my G70 fits snug..
Your mod would have made the BK9 fit perfect.. in the slim.
Now with my $230 ProGo 76 bag, I can use it to protect the $75 Casio too
BTW: The road runner bag(61 size) at GC fits E-A7 perfectly.. (1/4 cost of ProGo)