Yup. I actually tried making an analog of electronics with water and air first. Water didn't work very well because of the high resistance. Air didn't work very well because of it's compressibility - each time it compresses and decompresses, there's serious hysteresis and you lose a ton of energy.The trickiest part to make in a mechanical version is the simplest part in electronics - the junction: Where one wire splits into two wires. I spent a lot of time trying to figure out how to do that with anything besides a fluid or a gas. Fortunately, planetary gear systems do the trick. Once I got that working, everything fell into place. Using a junction, you can easily make parallel circuits. Capacitors are just torsion springs in the spintronics model.