A small mechanical train was the first toy that I dismantled just to find out how it worked.
Try very hard to come up with a totally original way to talk about this, because unfortunately a lot of students tell about their childhood love of taking things apart to see how they work. Hundreds of essays like that are written each year.
So, make it original and funny if you can.
meddling with mechanisms---Awesome. You are not only an engineer but also a wordsmith, and engineer of awesome sentences.
Great job, but if you can find a word of phrase to use as a theme, a memorable theme, something that unites the 2 or 3 main ideas you express here, that will make the essay perfect. Give it a theme so that if someone asks me, "What is it about?" I can tell them easily in a few words.