Hi, welcome to the forum.
Hollandia plate like the name suggest Dutch and made in Holland/The Netherlands. We call it
Hotel Silver or better silver plate ware for restaurants & hotels. The factory: Fabriek van 'Hollandia Plate NV' city of Hilversum, opened in 1919 and made exclusively cutlery and items for restaurants, shipping, etc. For large users.
http://www.iisg.nl/ondernemers/pdf/pers-1117-02.pdfhttp://zoeken.gooienvechthistorisch.nl/ ... =210414844In 1963 the Gerofabriek took over the Hollandia Plate factory in Hilversum and the brand: Gero-Hollandia Plate came into use.
https://www.statengeneraaldigitaal.nl/d ... &pagina=171963 1. Fusie De N.V. Gerofabriek, te Zeist, heeft de N.V. Hollandia Plate, te Hilversum, overgenomen. De ondernemingen zijn produktieverwant. Het Hilversumse bedrijf vervaardigt hotel-zilver. Gero heeft met deze fusie haar reeds krachtige positie in de couvertindustrie verder versterkt.1963 1. Fusion The N.V. Gerofabriek, in Zeist, has taken over the N.V. Hollandia Plate, in Hilversum. The companies are production related. The Hilversum company manufactures hotel silver. With this merger, Gero has further strengthened its already strong position in the cutlery industry.See Gero

For Gero see;
viewtopic.php?f=5&t=28590#p70278Peter.