I was rather like that as a kid. Meccano, Fisher Teknik are both good because you can build a wide range of rather complicated "creations". Old clocks are good

I was rather like that as a kid. Meccano, Fisher Teknik are both good because you can build a wide range of rather complicated "creations". Old clocks are good because the pieces are rather large and ideally can be re-assembled and made to work again as well. Around that age I was given a motorcycle battery and a variety of bulbs, relays and car parts. Unfortunately these days, electronics and miniaturization has reduced the scope of what can be educationally taken apart.