I have not fumed cherry, but have fumed a lot of white oak for furniture. For small pieces like a pistol stock, you can use something like a large piece of Tupperware for a fuming chamber with a couple of wood waste blocks for support. It works better to have concentrated ammonia from a chemical supply. The stuff is potent and should be handled using a proper respirator in a well ventilated area.
You should know that results of fuming seem to vary with every individual piece of wood. Also part of the reason for using fuming is that it colors both the harder and softer parts of the wood more evenly, making patterns in the wood more subtle rather than more pronounced. When people desire to make a maximum contrast in the wood, fuming is not the process of choice. The idea of subtle variation rather than startling contrast seems rather out of modern style IMO.
Fuming is a rewarding process to learn, but needs to be approached with safety in mind. Some people "safen" the process by using dilute grocery store ammonia, they generally produce dilute results.