That your time and get LOTS of references.
Don't use anybody elses model as reference beside I've yet to see a correct Steamrunner done. I think the ST magazine is supposed to be drawing up blueprints for it soon.
SFA's is done wrong according the the 3rdedition ST enc. And Dan Hurlings is too personalized. Hell even the CGI model used for the show shots is lame looking!
I'd start with the nacelles first, the secondary/deflector hull second, and the saucer last do to it's complexity.
Hell I'm still working on mine! Got stuck on the saucer 'fangs'
chrono