I know that Samsung TV's will display the MUX information when press+holding the button "Info" until
the information appears on the screen, so maybe you could track down someone
with Samsung TV, and there may be other brands able to display such a information.
I remember when in Cuba and trying to get more information about their DTV service "DTMB",
people just do not understand technology now and why you would like to watch TV on PC etc.
Also reviewing manual for the TV can sometimes yield useful information :)
Visiting shop that sells TV as well as I have done it in Costa Rica and their DTV standard "ISDB-T" :)
I actually went to the office of the Ministerio de Ciencia, Innovación, Tecnología y Telecomunicaciones
in San Jose there was just one guy that understud it and had all the dongles, antennas etc that the Japanese
donated to them so I got straight to the source :) Maybe a visit to VTR could be the option.
You are from EU and interested in the technology deployed by them ........
Looking at the models sold there and then looking up online information about the TV's one may have a clue in the manual ....
Out of interest, can you get some model numbers of TV's currently sold there to work with "Cable TV" providers, if any?
Calling in VTR engineer to fix problem (that does not exist) with TV signal and having a friendly chat could lead to some information etc. :)
What working TV/Box do you have access to?