 The mechanical parts were assembled in the fifth @-@ floor area in November 1975 , using a non @-@ original Mangel @-@ Illions mechanism . A Wurlitzer carousel organ , which had belonged to an amusement park in San Francisco , was added . Before it was installed in the Children 's Museum , the organ was refurbished and rebuilt by Carval Stoots of Plainfield , Indiana , in 1976 . 
