Hello Forfarian, that is the only information I have about William. I can’t make out Eliza’s marital status in 1851 but I believe she says she’s a widow in 1861. I have not been able to find an actual marriage record for William and Eliza.
So the one and only time I see William is in 1841.
But I do have a theory. In 1850, there is a William living with George Johnston born 1808 living in New York. William is 33 born in Scotland but the relationship to George is not given. George died Sept 3, 1883. George had married Jeanie Deward/Dow Orr Aug 29, 1835 in Ardrossan, Ayr, Scotland. George, a baker, and Jeanie are found in 1841 in Gorbals, Lanarkshire with children William, Elizabeth F., Hellen, and Jane A. These are the same children in the same birth order that are in Johnstown, Fulton Co. New York in 1850, along with William age 33. I don’t find William again.
But in 1875, William’s daughter Elizabeth now married to George J. Logan is living next door to George Johnston.
When George died in 1883, his age was 75 years five months 24 days so I work that back to April 10, 1808. I found the birth of a George Johnston, April 24, 1808 in Chirnside and his parents were George Johnston and Elizabeth fish and he named his first daughter Elizabeth fish Johnston. So my theory is that George was born in Chirnside and William is his brother, but I can’t find William’s birth.