Hi Mauro,
The Dutch company 'MFT' (Metaalwarenfabriek Tilburg), originally 'Hollandia' made these magazines for Mausers from the early 70s until Mauser production was halted. Originally they made the full magazines, later they only supplied the tubes to Mauser. MFT also produced the HSc magazines for Mauser.
In order to try and gain a small profit (they didn't make much on the Mauser mags) they produced a batch for Interams in the USA. These were labeled 'Made in Holland' and 'Mauser'. Mauser objected to using their name and the second batch for Interarms was simply labeled 'Made in Holland'.
They were also supplied with the original Mauser Parabellum. These were simply marked 'Mauser', nothing else.
Interestingly, the follower button was never produced in the Netherlands. These appear to have been made in Switzerland....
Nico van Gijn, a Dutch collector contacted MFT in the past and succeeded in obtaining a number of magazines, the dimensional example Mauser supplied to MFT (a Haenel
) and a number of incomplete, unfinished tubes.