That's very interesting!

The only problem is that
the Akai MPK49 is a controller, not a synth, so it doesn't generate any sounds itself.
seanstephensen, what are you using the MPK49 with-- which DAW, what soft synths (if any), what other virtual instruments, etc.? It seems like the easiest solution would be some sort of script that alters the MIDI note numbers being received, something along the line of the following:
New_Note = 124 - Old_Note
If New_Note < 0 Then New_Note = New_Note + 12
[or: If New_Note < 0 Then New_Note = 0] *
The above isn't an actual script, just simple pseudocode. It assumes that you'd want to flip the keyboard such that Middle C would become note 64, as follows:
(Edit: I mean that the Middle C key on the keyboard would play note 64, or the E above Middle C.)
( * Edit #2: On some keyboards if you shift the octave up or down beyond the valid MIDI note range, 0 - 127, the keys that fall outside the valid range are bumped back an octave to put them back within the valid range.)
I've never tried to do any scripting in a DAW, so I don't know what's possible, but it would at least help to have some idea what you've got to work with.