Thanks for the comments, they have been most encouraging

For the reasons gevatter Lars mentioned, the sail stays. It's a crucial part of this vessel, though there are others that don't have sails and look like regular warships.
The original intent was to create an AeroTech mod (no mechs and ground stuff, just the spacecraft - Warships, Jumpships, Dropships), and I've got maybe half a dozen fighters and one or two larger vessels in various stages of completion from over the past 6 months. Unfortunately I am involved with other non-Freespace projects, so I haven't had the opportunity to jump very far into FS2 modding, and probably won't be able to carry the planned mod into fruition, at least not alone. But I will see if I can put some more effort into this model, like some proper texturing, submodels, weapons etc. and produce something more presentable.