I had to test some part of the multicast setup on the work network and fired up VLC. And from the department of 'some things never change' or 'still going strong', Bratislava STV2 testcard is still available under the title 'Monoskop' on vlc url rtp://@233.10.47.73:1234. This stream must have been going for years, I remember using it in tests years ago. And during the day when STV2 has no program, it still transmits an actual Philips PM5544 testcard.