Hello, I just found out about the Dark Mod although being a fan of the original Thief-games since the day those originally came out. Since the title's question is not really mentioned anywhere, I doubt that has never been the aim of this project, but I had to ask. One would wonder would the old maps be even remotely useable by id Tech 4-engine? And once again, apparently not, so could those maps be converted to TDM-maps? Yes proprietary things and all, but naturally one would have to have the original resources available yes.
You might want to consider adding a FAQ-section to website.