Hello Steve,
Although I don't have the definitive answer, I think you are looking for the archives:
3868 Ambachts- en Gemeentebestuur van Heemstede (Gemeente Heemstede) and
3862 Heerlijkheid Heemstede
at the Noord-Hollands Archief. Just send them and email at "Inlichtingen at noord-hollandsarchief.nl" (email adres deliberately altered here).
Michaël
Thanks, Michaël! I'll email them.
Regards,
Steve