To the right, destroy the furniture. Then build the grapple plug. Grapple and solve the riddle with Erin. The shapes are scattered on paintings in this room. The correct order is Diamond, Triangle, Square.
The blow from Minikit 6 left some parts next to the canon. Build and turn the canon. Then use Relic Detector to find the Grapple. Then Master Build a heater in the back left corner. Drive back to the Present with the DeLorean. Use Magic, Laser and Grapple on the heater and build bellows. Jump on the bellows a couple of times until the heater blows up. Pick up the Minikit.
There is a puzzle upstairs to the right, next to a brown door. Story related, you have to use Intelligence on that puzzleto get to the 3 blue plugs for the hanging cloth at the center. After you've done that, go back and do the puzzle again. A statue will come out. Push that down as well to get the Minikit.