John,
I don't know if these two (2) threads are of interest to you or Ken, but Art Bergeron, Alan Pitts and I had some fairly length discussions about the engagements of March 25th and later on the west end of the Petersburg defenses. Here are links to the beginning of the threads in the ALCWMB Archives.
http://history-sites.com/alcwmb/old-archive/archivefiles/6256.html
http://history-sites.com/mb/cw/alcwmb/archive_index.cgi?read=4145
I'd be very interested in any additional information you have on the battle of Watkins Farm (Mar 25) or Gracie's Brigade.
Jim Martin