This is the Royal System:
It's a modular, wall-mounted shelving system in teak, first created in the late 1940s by Poul Cadovius.
The basic design, of uprights from which shelves are hung with brass supports is also used in other systems, which I think were based on the Royal System.
There's the Randers Møbelfabrik PS System, by Preben Sørensen: .
And Sven Ellekaer's design for Albert Hansen .
Any others from the same era?
I noticed that now even IKEA are doing their version: . It looks OK, but frankly bamboo doesn't can't match teak.
And a company is making the Royal System (sort of, they've messed it about a bit) again: .
Daniele