In 1959 (some sources say 1962), Bestbox started making simple diecast cars in Limburg province (Bickford 2009). The Dutch Wiki site reports that in the 1960s, the coal mines in Limburg closed. Some significant post-mining industries where workers relocated were automobile producers DAF and Nedcar in Born. After the closure, DSM (The Dutch State Mines) tried providing new employment to out-of-work or disabled miners in different shops or factories. These 'WIM' workshops (Workshop for Disabled Miners) were backed by a national Fund for Social Institutions (FSI).
One of the activities was to continue the production of Best-box models. Later the name was changed to EFSI, apparently a phonetic pronunciation of FSI (EFSI Dutch Wiki page; see also EFSI Made in Holland, 2010–2011). The Bestbox name was discontinued in 1971, perhaps because of the similarity to the name (and competition) of Matchbox toys (Breithaupt 2001). Though similar to Matchbox, and popular locally, Efsi toys do not seem to have been too well known outside the Netherlands (Rixon 2005, p. 85). Most Efsi products were marked "Made in Holland" (as opposed to 'Made in the Netherlands') on the base.