Peggy, I may have a match. On the Baden Immigration Index there is a record of a Gabriel KNAB seeking permission to emigrate in 1853. The record states Gabriel is from Unzhurst, Germany. My Knab ancestors are from Unzhurst. You can trace this line using FHL # 1045112.
I am also searching for a Gabriel Knab, born 10 April 1830 who died in America. He was born to Franz Joseph Knab and Ursula Hauns. Their marriage was 30 April 1814. The 6 children of Knab/Hauns are on FHL #1045114.
We believe our Knab ancestor, Martin Knab born 6 Nov 1791 in Unzhurst, immigrated to NY with his wife Maria Anna Bohn, in 1831.Martin had moved from Unzhurst to Moos.
This Gabriel would be a nephew to our Martin Knab. Martin is a brother to Gabriel's father Franz Joseph Knab. Franz Joseph was born 7 March 1790 in Unzhurst to parents Franz Henri Knab and Elizabeth Storz.
Franz Henri, born 4 Oct 1763, is the son of Joseph Knab and Anna Maria Seiler. I can provide more generations.