If you have a file object of a cached file, there’s an even better command to find the file data in the cache: !finddata. It takes a file object and an offset and shows you the data in the cache at that file offset.
Unfortunately, just ran it against the system I’m on right now and hit an error:
What’s odd though is that I’m able to see the VACB fine:
So I’ll send a bug to the WinDBG folks using the feedback link available at the bottom of every documentation page.