If the jpg image doesn't have exif header you need to create it first:
jhead -mkexif
Then enter the time stamp data:
jhead -ts2009:08:15-10:30:00
Get the boot floppy image from the RedHat site and write it to a floppy. The floppy should not be mounted while writing:
dd if=boot.img of=/dev/fd0
That's actually the command to write any floppy image back to a floppy.