Alex Hill over on ML found this very interesting film clip on the British Pathe site:

It shows a train loaded w/M4A2s (75 d, 47 degree hull) along with Cromwells and a few 6pdr Valentines. It had been said that only a four Cromwells were sent for evaluation purposes only. In this strip, we see many more than that. Very cool find!

http://www.britishpathe.com/still_image.php?id=64835&frame=15&size=d1

http://www.britishpathe.com/still_image.php?id=64835&frame=158&size=d1

http://www.britishpathe.com/still_image.php?id=64835&frame=51&size=d1

http://www.britishpathe.com/still_image.php?id=64835&frame=41&size=d1

http://www.britishpathe.com/still_image.php?id=64835&frame=50&size=d1

The whole clip's index can be found here:
http://www.britishpathe.com/thumbnails.php?id=64835