6989-1 (Inv) Mega Core Magnetizer / Multi Core Magnetizer 473 Parts, 3 Minifigures, 1990 Sets: Space: M:Tron
* Change 2 Part Black {3794 Plate, Modified 1 x 2 with 1 Stud (Jumper) (Undetermined Type) to 3794a Plate, Modified 1 x 2 with 1 Stud without Groove (Jumper)}
Comments from Submitter:
All 20th century jumpers are the same, ungrooved type