I was in Brussels this summer and came across the town of Overijse on the south and east side. There I found a restaurant named Masion Istas or Huis Istas. On the old pictures it also has Joseph Istas as the owner. Also on the photos there shows the building to have been a tobacco shop and perhaps a saloon. They used to brew beer there from what the locals told me.
To make a long story longer,,,
My father-in-law was Leo Ernest Istas, his father was Octave S. Istas, his father was John Istas, born 1845 in Belgium.
Does anybody know who John Istas' father would be?