The BBC did indeed buy LDK5s for use on outside broadcasts. The use of Triax cable was a joy beyond belief after multi core cables. I don't have the exact dates to hand but they lasted over a decade on OBs and were excellent value for money. They also bought LDK25s ( the cheaper cable version) for use in studios. They also bought Link 109s, 110, 111, 120s, 125 and would have bought the 130 if Link had not gone bust.
You have to realise that the BBC, as a national broadcaster, was (is) big enough to purchase the best cameras from a range of different manufacturers to avoid accusations favouritism.
I have two LDK5s in the museums collection, one BBC and one Thames. Yes Thames thought they were excellent cameras too.
I don't have figures for how many were made, it would be nice to know.
Brian S
www.tvcameramuseum.org
PS. I have not done the LDK5 pages yet so no point in looking.