The 1957 Caledonian Kitchen Car Bogies

[proton]

Now that we all know, from the lovely Hornby models,  that the LMS Coronation Scot kitchen cars had 8' and not 9' bogies, it raises the question for me about the bogies used under the kitchen cars used on the Caledonian when it was introduced in 1957.  Did British Rail replace the LNWR 8' bogies under the cars, or were they retained?  Photographic evidence would be nice.  Does anyone know?

 

John