Now that is funny...given the almost total ORAL history tradition in most Chinese Styles and the complete BS that most people will argue about in regards to history.
The first part of historical depiction:
If the tassels were ornamental or purely for show and not used in battle (possibly true if tasseles and flags were used at all ) Then the depiction in a museum would be inaccurate only if they were shown in combat situations. If they were shown in display...no big thing.
If the sword being show was one that belonged to a noble...was it a ceremonial weapon (never seen use) or a real combat one....
Again, there is a lot of room for interpretation there.
Historical inaccuracies abound. I can quote chapter and verson the origins of styles...as in how many styles tie back to Yueh Fei. Orgins of styles, use, hero tales, etc... .
The issue of weapon weight...an issue in competition for ages. I know plenty of Traditional folks that use heavy but badly made weapons. I also know of plenty that claim traditional and then spend ages going though weapons to pick out the lightest one...not the best balanced or most comfortable as a traditional person would be thought to do..