Scouts build a lego model as instructed by their PL who has the instruction guide but is not able to touch a single lego block.
Multiple complete lego kits of varying challenge levels, tables
Patrol Leader to be issued with the instructions for a model, with the parts presented to the patrol.
The Patrol are not allowed to look at the plan, likewise the PL cannot touch any piece of lego.
PL is to direct the scouts in constructing the model that they have the instructions for.
Repeat with models of greater challenge if need be.