Just a thought, if you contact the Bristol industrial society and try to either obtain a copy of their journal below or the author I am sure the article will be of interest as it has several pictures taken on board shortly after her completion. keith is an absolute gold mine of information about SS Great Eastern, he has madea rather large model of her which is in the NMM.
title author journal_no publish_date
GreatEastern:FeedwaterHeating.TheAchillesHeal Keith Hickman 36 2004
The link for the society is
http://www.b-i-a-s.org.uk/BIAS_contact.html