Former Owner of Ka Nefer Nefer Mask Victim of State Repression?

SLAM and the Socialist Federal
Republic of Yugoslavia

I recently discussed the part of the collecting history of the Ka Nefer Nefer mask referring to the period when it is claimed the antiquity was in the Socialist Federal Republic of Yugoslavia and the disappearing of suspected "enemies of the state" by the State Security Administration (Управа државне безбедности - UDBA) in the early 1960s when the mask changed hands (PACHI Thursday, 21 August 2014, 'SLAM's Ka Nefer Nefer and Questions About the Communist Regime of Yugoslavia'). The question is raised again  by the publication in the German media of an article about Tito's assassination squads ('Murder in Tito’s Name: German Journalists Investigate Liquidations by Yugoslav Secret Police', Balkanist January 5, 2015). 

The problem is that despite a number of years' research, both before and after its purchase by SLAM, not a single trace has been found of any documentation of even the former existence of the first known owner of the mask in the SFRY, a person (of indeterminate sex) whose surname is given as Kaloterna, which is an uncommon form. The only mention of the former existence of this person has been a chance remark made by its second known owner, a person apparently closely related to the ruling elite of the Communist state after 1964, Zuzi Jelinek, who by her own account acquired this valuable antiquity precisely in this period. Under what circumstances did the Kaloterna family relinquish ownership of this mask and under what circumstances did a Tito family confidant come into its possession?

What happened to Kaloterna, and why is there today apparently zero documentation of this person's existence? Does Mrs Jelinek have any further information on the identity and fate of this individual? When asked by a US journalist, she was very vague about the whole affair: "I bought the mask many many years ago, and I sold it many many years ago". One might quite legitimately ask, whether there is a possibility that the lack of information about this individual means that Kaloterna was 'disappeared' by the Socialist Federal Republic of Yugoslavia's State Security Apparatus for political reasons.

Communist leader Josip Broz Tito examines a vase with wife Jovanka...

US museums are very careful about checking acquisitions which might be 'Holocaust Art' appropriated by state authorities under the Nazis, perhaps they need to take equal care not to acquire items taken from their owners in former Communist states during the so-called Cold War. Perhaps those who forked out money so SLAM could buy this object deserve to know a little more about the nature and circumstances of this transaction deep in the heart of Communism. That's:

Friends Fund and funds given by Mr. and Mrs. Christian B. Peper, Mrs. Drew Philpott, the Longmire Fund of the Saint Louis Community Foundation, The Arthur and Helen Baer Charitable Foundation, an anonymous donor, Gary Wolff, Mrs. Marjorie M. Getty, by exchange, Florence Heiman in memory of her husband, Theodore Heiman, Ellen D. Thompson, by exchange, Dr. and Mrs. G. R. Hansen, Sid Goldstein in memory of Donna and Earl Jacobs, Friends Fund, by exchange, and Museum Purchase

These people placed their trust in the trustees and staff of the Museum to sort out questions like this before approving the purchase, is there any evidence that this trust was justified? What has SLAM determined about the fate of Kaloterna and the Kaloterna collection in Communist Yugoslavia? Where are the Kaloterna heirs?