I spliced it off the PR1.3 firmware image (DFL61_HARMATTAN_40.2012.21-3_PR_LEGACY_001-OEM1-958_ARM.bin, actually) with the Maemo version of flasher, which understands the --unpack flag. Nokia seems to have removed that option (propably as a security-by-obscurity-measures reason) from the Harmattan version of the flasher utility, but fortunately the older flasher understands the Harmattan FIASCO images too