Michael Zoellner sez,
Unfortunately I could not find a single vector graphic or 3D model anywhere. There are articles about the history of the graphics, Peter Saville's artwork and PSR B1919+21. I even tried to visualize PSR B1919+21's waveforms. But in the end I spend an evening tracing the waves by hand.
The resulting SVG file was extruded and rendered in Processing with Richard Marxer's Geomerative and my RExtrudedMesh extension. OBJ export was accomplished with OBJExport. The model was printed on Makerbot Replicator with white PLA filament.