You should not have deleted my findings so quickly, when Mary Martha got married in 1835 her paternal grandparents were listed: Pieter van Es and Lena de Jong, since she is Leendert's sister, (Leendert van Ess (1791-1826) who was married to Martha van Driel), they would also be the paternal grandparents of Leendert, and the parents of Pieter married to Trijntje Meijer.
I did list them, if you would have followed my thread you would have seen how I got them.
Both Pieter and Lena were buried in Leiden, ZH so the search would likely continue there. https://familysearch.org/pal:/MM9.3.1/TH-1-17699-107790-93?c...
page 791: Burial extract for Pieter van Es, buried 25 Feb 1797
at Papegaaij? Bolwerk? in Leiden