Dave,
Oh yes, I'll just go get the book on Sumpter Valley Steam Shovels Volume X, it's in the well recieved maintenance of way series! These pictures have never even been seen by most people and now you want a side shot!?! What a bloody toad you are! Anyway, this might help a little, I cropped the image down to just show the Marion. It's hard to tell if the whole body swiveled, but I think it did as it appears that the Marion is widening a cut in this picture, and that it would have to rotate to dig and then turn to drop the dirt on the waiting train. Unless the boom had a rather wide reach, I don't think you could do this move. Plus, if you look at the alignment, the body is not in line with the frame in this picture.
I'll search through more pictures as well to see if the Marion shows up.
Also, it appears that the shovel was oil fired as it seems the wood compartment of the accompanying tender is blanked off. And looking at the grab on that little tender tank....I think it might still exist, but I'll have to do some research.
Enjoy, Taylor