Cornelis lived on a large farm on the CLEYWEGH. This was the road between Reeuwijk and Gouda and this neighbourhood was called Bloemendaal.
When Cornelis went tot pay his taxes, so the story goes, the civil servant added the name VAN CLEY to his first name, because last names were then required. ( This information from Ton Verkley in Nijmegen.)
The spelling changed to VERKLEIJ sometime after 1720. The spelling ofVAN or VAN DE often was changed to VER as in: van Rijn to Verrijn
The spelling of the name in the early days could be; VERKLEIJ, VERCLEY, VERKLEIJN, VAN DER KLEIJ, , VAN DER CLEIJ, VERKLAIJ, VERKLEI.
His grandson Maarten Cornelissen had the name VAN DER KLEIJ.
The name also appears in Wassenaar near the Hague in the 1600's as van der Cleij and in Reeuwijk in the 1700's as van der Kleij. The name Verkleij is unique and started in early 1600.
I believe that despite the different spellings, all are related.
The birthdates of "de Oude" and "de Jonge" are estimated.
There is a record of marriages of Jan Corneliszn Vercley on April 30 1634,
and Maritgen Cornelisdr Vercley on Apr 17 1633 and May 3 1633.
(The first date may be the civil wedding, the second one the church wedding.)
I strongly believe they are brother and sister of Cornelis Corneliszn"de Oude". !!