SL Perrong - Spherical Speakers Speaker set

Beautiful globe-shaped speakers from the 1950s of the last century.
It has a very sturdy steel back and a chrome-plated grille at the front.

I bought these speakers a few years ago in Sweden.
The previous owner told me the history of the speakers.
He gave them the name SL Perrong speaker from the 40s-50s. Perrong is perron in Swedish.

The speakers hung on a platform at a train station,
When the platform was renovated the man was allowed to take the speakers with him.

I have used them for years as speakers in my 2 Old Timers.
Recently I bought other speakers for that purpose, so these are now redundant.

In a final test one speaker did not work.
Upon inspection there was a Full Range speaker inside the domes.
I replaced the speaker with a
Visaton R 10 S - 4 4" Full-Range Speaker 4 Ohm
20Watt RMS and 30Watt max.

Inside the domes there is also a bit of technology, it looks like a filter.
The filter is controlled by a 3-position switch that can be adjusted from the outside of the dome with a screwdriver.
There is also a 2-position switch.
I never fully understood what these switches were for; I was satisfied with the sound that came out.

See the last photos for a peek inside the dome from which I replaced the speaker.

Good luck bidding on this special lot.

Of course I will pack it carefully and ship insured.