I am looking for a clear close up photograph of a manual air valve like you might use to control a diesel horn. This is for a graphics project - I am mocking up an interface to make it feel like you are running a train. All the photos I find show the valve from the side. I have found a few that are almost overhead, but they are usually from an angle or not really usable. Can anyone please direct me to an overhead photo, or if anyone owns one of these valves, could you possibly take an overhead photo of it? I don't have a specific loco in mind - as long as it is you can tell what it is by looking. Much appreciated.