Mr Janssen 1961 Wonji-shoa Ethiopia

I am looking for the present adress or status of Mr Janssen , a Dutch Engineer ( Technician ) , who has worked in Ethiopia In Wonji-shoa Sugar factory and Metahara during the late 1950s and early 60's Under the HVA - STORK companies of Netherlands.
I would like to send old photographs to any one with important information. Any help and response is highly appreciated.
Thank you