Charles Gesner van der Voort (1916-1991) has been a member of NRCV (Nederlandse Reünisten Vereniging China (NRVC, Dutch Reunists Association China), as well as most of his former colleagues at Holland-China Trading Company.
NRVC evolved from Nederlandsch-Chineesche Vereeniging which was founded in 1923, by people who had an interest in China. Most of them had worked there, or studied Chinese and Chinese culture. Its magazine "China" had its editors' address at Leidsestraat 82-84 in Amsterdam, where Netherlands Harbour Works had its head office.
Its main activities before WWII were along the China coast: Shanghai, Hong Kong, Macao, Yantai (Chefoo), Xiamen (Amoy), etc.
Netherlands Harbour Works Company was founded 1 July 1912. More of its history is available online in the doctoral thesis by Frans-Paul van der Putten, Leiden University, "Corporate Behaviour and Political Risk, Dutch Companies in China, 1903-1941". <a href="https://openaccess.leidenuniv.nl/handle/1887/15900" rel="noreferrer nofollow">openaccess.leidenuniv.nl/handle/1887/15900</a>
<a href="https://020apps.nl/kaart/1850-1940/Leidsestraat/82-84" rel="noreferrer nofollow">020apps.nl/kaart/1850-1940/Leidsestraat/82-84</a>:
[translation Pieter Lommerse] "Office building at the corner of Prinsengracht [and Leidsestraat] of N.V. Levensverzekeringsmaatschappij 'De Nederlanden', from 1954 'De Nederlanden van 1870'. Therefore, the building was named 'De Nederlanden'.
The insurance company used part of the offices, the other offices were rented to other companies {, one of which was Netherlands Harbour Works, or Nederlandsche Maatschappij voor Havenwerken].
The retail spaces at ground floor were rented to a furniture shop and to Municipal Gas Works. It displayed and sold gas stoves and fireplaces, up to 1921. From 1921 to 1994 a restaurant by the name of Dikker & Thijs was run here; there is still a hotel by that name."
photo by Pieter Lommerse
Source: This image came from Flickr, see https://flickr.com/photo.gne?id=49331278153