You need to patch your ms28 key into Hitachi firmware and make sure it reports as ms28. You can do this with Toolbox 3.1. Then flash that firmware to the Hitachi following the section in Textbook's tutorial for 0059 drives.
And no, of course you can't put Samsung iXtreme firmware on a Hitachi. If you could everyone would simply do that. There is a Hitachi version of iXtreme in the works that should be out soon.
