There is a way to 'pin' a package in APT as well. Then its on hold, and won't be upgraded. I forgot how to do this though, but its possible. Then you can stay with old map version easily.
echo "packagename hold"|dpkg --set-selections
Put the .so in your homedir and then try e.g. $ LD_PRELOAD=/home/user/libfaketimeMT.so.1 \ FAKETIME="-60 d" navicore