What types of "alterations" are inappropriate?

Resizing an antique by cutting portions of it down is the most common and inappropriate alteration made to furniture. This has happened with many sideboards, bookcases, and side tables. Replacing key elements (like replacing Marlborough legs with cabriole legs) to “improve” the appearance of a piece is also not an honest restoration. A marriage of antique furniture (making up a piece by putting together similar looking but otherwise unrelated pieces) is also inappropriate. Of course, intentional fakes made from new timber made to look old is not only inappropriate, it is fraudulent.

Shown below: A Rare Pair of 16th Century Roman Metal Cartouche Appliqués (pronounced "ap luh KAYS")
List price: $60,750 USD