It happened here in Australia too! Station ATV-Melbourne was the host station for Lewis/Young Productions, and later, Television House to produce the legendary "Young Talent Time" which ran from April, 1971 to December, 1988. But there are 800+ editions of the show gone because the tapes were "wiped" on orders from station management to preserve tape for other shows. I sincerely hope Johnny Young managed to preserve his own copies of those editions as there are so many golden moments from that show that I'd hate to think were lost to us forever.