The ETF has a database of surviving sets
https://www.earlytelevision.org/prewar_database.html
There were two collectors in the Los Angeles area that had TRK-12s. These two collectors have both passed away. There was another TRK-12 which sold on eBay last year in Temecula CA about 65 miles east of LA. There was another by a collector up north of LA. There may be a TRK-12 up in the San Francisco Bay area owned by a member of the California Historical Radio Society (CHRS).