Hi to both of you,
The "Nondestructve" install is simple.
a. Make sure there is enough space for e-smith (for linux partition).
    If not, create some (e.g. by FIPS).
b. Edit ks.cfg file on Install floppy:
   # partitioning parameters
   zerombr yes
   clearpart --all
change to
   # partitioning parameters
   zerombr no
   clearpart --linux
and
   # boot loader
   lilo --append "ether=0,0,eth1" --location mbr
to
  # boot loader
  lilo --append "ether=0,0,eth1" --location partition
Above implies use of boot floppy (created during install) to  boot e-smith
and leave unchanged your normal boot to gatesware.
Happy experiments!!
eddy