Thank you mrburnette! I've read the intel hex format from wiki. Saved first file you posted in my dropbox reference folder. Intel stuff brings some of my lost memories from the 90's. My other thread is converging with this one.
I was able to combine a sketch and a bootloader hex, removing the end of record line. I then used Nick Gammon's sd card flash program. But the program insists that it should use a fuse value that runs code from 0000, not from the bootloader address, and it refuses me to change the bits to the right value to run the bootloader, so yes, I did that but no the bootloader was just dead weight.
I got to change his code so I can programmatically flash a target if the source arduino downloads an update from our servers. That's going to be cool.