Hamstra Family Ancestors

This image was found in the book "Inscriptiones Van Buchel" p99, and as of 29-Dec-2020 can be found at: https://objects.library.uu.nl/reader/index.php?obj=1874-20266&lan=en#page//93/53/12/93531286164527595482847670260816510072.jpg/mode/1up
The inscription reads: "Hier leyt begrave meester Cornelis de Jonge, eerste raet ordinaris, en na rekenmr van Hollant was, die starf A(o) 1504, den derden in marte ende joffr. Mechtelt vander Merwede, syn huysfrou, starf a(o) XV(c)."
The Dutch translation provided: "Mr. Cornelis de Jonge[2], eerst gewoon raadsheer, later rekenmeester van Holland, ligt hier begraven, hij stierf 3 maart 1504; en Mechteld van der Merwede, zijn vrouw, stierf in 1500."
In English: "Mr. Cornelis de Jonge[2], first just counselor, later mathematician from Holland, is buried here, he died March 3, 1504; and Mechteld van der Merwede, his wife, died in 1500."
The Dutch translation provides a reference: 2 Heer van Baardwijk, zie Die Haghe 1981, p. 47.