Dmc874, it's work.

1. In your program in dir iPAQDISK I see header.img and iPAQROM.img, summary size 4196904.
2. In dir c:\ipaq\sp30391, which created after install official update (version of ROM 1.11.10 ENG in this example) from HP I see iPAQROM.nbf too. Size of iPAQROM.nbf is 4196904 too.
3. With any program (for example, FAR) in "hand"-mode separate this iPAQROM.nbf from HP on two part. First part must have size equal your header.img, second part - remainder. Renamed both part in header.img and iPAQROM.img, copy both to the dir with replacing original header.img and iPAQROM.img, mount drive and make changes in mounted drive and make ROM with your program and flash PDA with TMOBILERST.zip. And see, that iPAQROM.nbf from official update (version of ROM 1.11.10) and iPAQROM.nbf from your program (on make it without cganges) is different. For example, I can't see any Tmobile's files.
4. IIWPO has been installed.

Thank you very much.