Duplo blocks are great for kids who like to build and take things apart.
Wooden train track set?
You can also get mini handy man sets with a proper workbench and some real tools - screwdrivers, pliers etc in a real tool box, and he can use that to work at. From age 2, these kinda kids really do take off in every aspect and you may find that having a designated space for him to work at gives everyone some peace of mind. Then you can just give him your old things to take apart (old small appliances for example)
