I think the Abene references are a little misleading. It has only superficial similarity to those – the head on the (opposite) side instead of the front. And that head is on a sliding ram with an additional Y-axis on the knee.
The photos taken from the right hand side of the machine look as if there is an additional vertical sliding surface, perpendicular to the knee ways and perpendicular to the ram ways so the whole head and ram can possibly be raised and lowered. It almost has two Z-axes and two Y-axes.
Google images will be your friend here.You have to try various combinations of 'Swiss milling machine', 'German milling machine', 'European milling machine'. These may give you some manufacturer names for further searches.
From the square shape and design of it (round, plasticated handwheels), to me it suggests late 1970's, early 1980's (compare and contrast the newer Abene models, Schaublin 22, later Deckels). The lathes site is better on the early machines than the later ones.
Another place to ask is anglo-swiss tools and the oldswissmachines io group.
If you remove a few covers, you might find date codes on some of the motors/electrics. That can narrow things down a bit.