To get a general idea of what a Priest flanger mechanism looked like and how it operated, take a look at
Figure 2409 in Dave Grandt's post
here. The mechanism is basically just a cylinder that pushes/pulls a few levers that in turn raise or lower a pair of flanger blades mounted on the pilot truck.
The cylinders could be mounted in any number of locations. The first photo in Chris Walker's post
here shows the cylinder mounted on the pilot deck of #268, painted silver and pointed to the sky.
On K-28s, the cylinder was mounted on the fireman's side right behind the pilot deck, as seen here on #473 (far upper right):
There was a heavy-duty bar that spanned the width of the locomotive frame with various levers attached to it that looked like this:
(sorry for the shoddy illustration, but its the best I can do)
And this connected to the blades themselves, which look like this:
All you guys that know
FAAAARRRRRRR more than I do... is that about right?