TBH i don't see any sign of major alteration on the nut slot. The compensated part is over the fretboard wood, but is plastiquy and kind of breaking. Like when you expose plastic to the sun. Another "bad point" when i bought this guitar was that i bought it without the OHSC, it came with an alternative, cheap one (hence the price i've got it). The guitar also came with a couple of paint cracks at the bridge pivot and another one beside de bridge hole (i guess trem was punished but not broken).
Serial number dates the guitar back to 2010 so i believe it might been before compensated nuts were the rule.
I guess i'll have to email MM to get more precise details.