You are very fortunate to have a son that wishes to participate in this activity. I hate to hear about the part breaking - I hope that experience does not discourage your son. Pugwash is right, this model has been around for a long time. I remember building this myself when I was about 18 or 19 years old - ha - that was about 45 years ago give and take a year or so -
If I remember this tea ship does not have any cannons - so, you all do not have to worry about rigging them. You can also leave the sails off and just rig the mast / yards, etc.