I found it difficult (and expensive) to source realistic looking caps for switches like the ones used in the Hornet, so I decided to make them myself. It takes a little practice and patience, but minimal equipment and skills to do produce decent looking switch-caps.
Cut a 40 mm (1,57") long piece from an aluminium rod. The diameter is up to you, I found 10 mm to be convenient. 1 m (39") of this cost 2,35 € (2,68 US$) at my local hardware store, so 1 switch cap roughly amounts to 10c :)
Chuck the piece to a drill and just use a file to shape it while it is turning. This kind of side load is going to ruin the bearings and chuck eventually, but this is no mass production either.
If you own an angle grinder, a Dremel or some tool of that kind, make use of it.
Take constant measurements, so you do not carve out too much...
Use a coarse file to cut the shape and finish off with a fine one.
Finally, use wet sand paper to produce a smooth surface.
Cut off the switch from the remaining rod.
Drill a hole in the exact center of the base matching the intended switch diameter and just stick it onto the switch. Maybe use some glue to fasten the cap.