So no 4.4.0-127 packages left in Synaptic but the /boot/vmlinuz-4.4.0-127-generic file remains? Then you can remove it manually
sudo rm /boot/vmlinuz-4.4.0-127-generic, same for other files that may be left behind without corresponding packages (hopefully none). And yes, I'd run a
sudo update-grubafter that to be sure. And that's it, all done. That was fun, right?!
You should now be able to update your kernel again (since -124 isn't the latest version) and you should be able to remove the others the normal way via Update Manager > View > Linux kernels to make room, where necessary (don't let it fill up again).