Abstract: An alignment device including a base plate, locking stem, locking plate and lock maintains the front and back sides of a pair of adjacent wall mounted panels of similar thickness in lateral alignment while an adhesive applied to the panels cures for providing a smooth front surface is provided. The base plate includes a lateral surface for bracing the pair of panels in a common lateral back plane. A locking plate includes a lateral surface for bracing the pair of panels in a common lateral front plane. A lock is carried by the locking plate for engaging the locking stem locking the locking plate firmly in place with respect to the base plate for sandwiching the adjacent panels between the locking plate and base plate maintaining the back sides of the adjacent panels along the common lateral back plane and the front sides of the adjacent panels along the common lateral front plane.

Abstract: A child theater booster seat A is combined with a second respective of a child theater booster seat A1 to form an assembly of children theater booster seats B. Assembly B is supported by a row of theater seats C having arm rests 10. Child theater booster seat A includes a seat platform 12 for seating a child, a first side wall 14, a second side wall 16, a first support arm 18, a second support arm 20. Interlocking assembly 21 interlocks booster seat A with a second respective of child theater booster seat A1. Interlocking assembly 21 includes a male extension 22 and a female receptacle 24.