After looking on line for a while I came across the Gusen Memorial Committee website which lists that gentleman's contact info as shown below.
My hope is that it is helpful some how
Vince...
By ordinary mail:
GUSEN MEMORIAL COMMITTEE
Attn: Mr. Rudolf A. Haunschmied
Sperlhang 4
4222 St. Georgen an der Gusen
AUSTRIA
By fax: ++43 7237 3946 FAX
By e-mail:
r.haunschmied@gusen.org