size=50 or size=100 both give me Error 73. It only completes successfully and generates the bin file if I use size=0.wait before you flash it! Push the super_patched.bin you just made to your PC as a backup and delete it off your phone to free up some space again. Also delete the whole /img subfolder so the script can start fresh. You might even want to disable backups in the options/config.ini file
Try generating another patched super image with size=50 or size=100
that should give you a little bit of extra free space to work with...
Then you can just pull the super_patched.bin to your PC and flash with fastboot
Motorola has fastboot support right?
adb pull /data/local/tmp/sysrw_1.42/img/super_patched.bin adb reboot bootloader fastboot flash super super_patched.bin
(Side note: I still have 2.3 GB free in internal storage after running size=0)