The component at the top is an SM tantalum cap. I would not use them for power supply bypass, as they have a reputation for spontaneously shorting and taking down said supply. The part in the middle looks suspiciously like a crystal for an oscillator, though it may also be a cap I don't recognize.. The bottom pic is of a sleazy phenolic open frame carbon trim pot. Those pots have a tendency to either come apart when abused (not very well put together), or develop opens after long service, as they are not protected from the elements at all. Sealed trim pots are much better bet all around.
3rd pic - First time I've seen a crystal/oscillator mounted like that - sure looked like a trim pot on cursory view...