Telecom device Televa RKL-203 found from local auction

Hey all, again nice find from local auction: some cind of telephone-connection/''router''. sorry, i don't know what is it in English ;D. but, here's the photos of it, feel free to comment.
and, why i bought it? just for curiosity/education, and the fact it was only about 20€ so not bad, considering good box, toggle switches etc....
the model is Televa RKL-203. Nameplate says also: REK-testing device, raw translation
There are none IC's used, all are discrete components. numeric rotational switch needs bit oil, or its spring is just stuck/dull. Relays probably use 48v, suggested in forums. I haven't tested this device yet, i have no idea how, but i think its pretty obsolete to use anyway.