There's none that I know of, Nick, though it would be great if there was. There are still Weazelops' advisor screen templates, but you probably already know about that. Etain did an incredible interface with a template to match, but sadly decided to leave CFC and erase all his stuff for reasons unknown. Tom's not around anymore and Balthasar is gone, so not many interface creators left. We do still have the ultimate cfc graphics stud here and of course he's always willing to answer questions.
What I would do when starting a new interface is create an art folder and dump all the art files (minus units) in first from the base game, then PTW, then Conquests. Some of the file paths were changed for conquest like science_industrial_new.pcx, but usually you just find those from trial and error. If there's anything specific you're looking forward let me know and hopefully I can help.