While admitting to my ignorance

when it come to dha, the descriptions and the vintage of the pieces in Hermann-Historica's auctions are not always accurate. They merely reflect whatever they have been told by the consignor.
For example, a keris were marked as being from Sumatra while the origin was clearly Bali, another piece was marked Sumbawa while it was Malay and so on.
Either way there were indeed some fine pieces in that auction, one just have to more or less identify the origin and vintage using your own experience and knowledge.