Well I was wrong in thinking 464 had a dog house in 1957. Just watched the film of the 1957 scenes switching in Durango, and alas no dog house as you guys suggested.
I made some notes however regarding the K28's and here is what I came up with...
478 has a Dog House in 1957(476 and 473 not seen)
476 has a dog house in 1961(473 and 478 not seen)
473 and 478 have a dog house in 1962(476 not seen)
The coverage in 1963 and 1964 is all freight
In the 1965 footage all three engines have their dog houses removed! Adios sometime between 62-65.
More useless trivia, eh!
Greg