twee /twiː/ adjective BRITISH excessively or affectedly quaint, pretty, or sentimental. "although the film's a bit twee, it's watchable" synonyms: quaint, sweet, bijou, dainty, pretty, pretty-pretty; More . Here it means not excessively something .... . Not a word you hear every day.

Thank you very much!

Like the other person said, it is rarely used, but in this example I would interpret this as meaning it was restored to as close to its original state as possible, without adding tacky gimmicks or quaint little features.