Perhaps there's a way to read the MBP1 file? I remember this could be done for MBP files, but this software is outdated now.
edit: Found this work around
http://www.buzzworthyapp.com/my-kind...lp/#workaround
Android is required (alas), but I'm posting if anyone else has the same issue. It involves downgrading to a version of the kindle app that existed before the mbp1 change. mbp1 is an encrypted version of mbp.