For what it's worth, and I must emphasise that I have no particular interest in whether or not another "parrafin can" escaped the torch: as a steam supporter these things are totally beneath me, the 1982 publication by the Diesel and Electric Group "Locomotive Directory. Every one there has ever been" gives the details for 55021 as cut up at Doncaster 01/1980; out of use for some two years previously.
This info was published before wikipedia, internet forums, websites, and mobile phones. BUT NOT BEFORE PRESERVATION SOCIETIES! The Deltic Preservation Society was a going concern back then and well clued up on what was happening, the cutting up of the first two 55's really spurred them in to action to raise the necessary funds.
Amused, 62440.
