Simulated furniture assembly

Total noob here.

I am trying to create a simulation where a piece of furniture is assembled piece by piece. I have part of it working. I built a class blueprint where the legs attach to the base one at a time when clicked, but now I want to insert a dowel into each leg before-hand as a first step.

My initial design concept was to have a series of class blueprints nested inside each other, but that doesn’t seem to work the way I anticipated. I wanted to keep the architecture as modular as possible so the objects’ functionality would be easier to apply physics at a later point. I want to integrate as much intelligence into the individual parts as possible.

What would be the best method to create this functionality?