"...I am now intrigued as to why anyone (anything) connected with a royal residence would be spending their time on a replica jewel. Why would they not display the real thing? (It does look replica to me.) "
One answer: royal exhibitions ! For example, the bridal exhibit at Palace Het Loo had Maxima's original bridal gown but with the replica tiara ! Same with the recent one which showed Princess Margriet's bridal gown but with a replica tiara too.