Well I tried to use WinHEX to do it manually and it did not come out right, was close but not valid. (I could see the copyright texts, etc but some letters were off a tad.)
I will try to install this in one of my spare A1000's. It would be cool to have Kickstart 1.2 in ROM. I would also like to try and do Kickstart 1.3, if I can figure out how to split the files properly!