"Shinbaden tapes" and timer tapes

[zandycap]

I have been wondering lately where the large amount of tapes came from, which appear to be taken from Timer copies and have clocks and similar things on the bottom or in the corners etc. A while back in one of the Usenet forums, a guy posted in and said he recognized some of them as what they called "Shinbaden" tapes, which were usually 16mm copies which were used for timing purposes and timing advert breaks in the right places etc.

Other tapes appear to be some sort of Master tapes and very good quality. Now i am certainly not looking a gift horse in the mouth. As far as I am concerned, anything is better than no tapes at all, and i am sorry if this question has been asked before. But do we know where these come from, were they secreted out of the buildings when it looked like they were for the furnace, or rescued from skips outside of the BBC or ITV stations, as we have heard did actually happen ? I remember Michael Palin telling of how they sneaked stuff out from the BBC themselves.