Keith,

You're right that it's a raw ETFS filesystem.  What you see are the first few inodes in every ETFS file. 

The only way to dump files out of an ETFS partition is by mounting the partition, and then extracting/replacing the 
files.  The only ways I can think of to do this are:

1. FTP to your target, and change the required files.

2. Transfer the raw image off the target, change it, and rewrite:
  a. Read the raw partition out of the target with etfsctl -R
  b. Mount it on a self-hosted machine with fs-etfs-ram
  c. Make whatever changes are necessary
  d. Erase the ETFS partition on the target with etfsctl -d <partition> -e
  e. Copy the new image onto the target with etfsctl -W

David