What is real vs modelled
Real, historical: the 4,000 t class vehicle, oil-film ablation protection, two-stage shock absorbers, the delivery gun, shaped-charge pulse units, the 1959 Putt-Putt flight, the 1963 treaty, and the era's Iₛₚ estimates (roughly 1,800-2,500 s) are from the declassified record (G. Dyson, Project Orion, 2002). Modelled: the geometry is a schematic, not a blueprint. The plate is drawn ~20 m across, where the record gives the 4,000 t design a 40 m plate and the 880 t test article 25 m. Δv per pulse (12 m/s·√kt), accelerations, magazine count and plate temperatures are first-order teaching estimates. The fireball and plasma jet are stylised and last far longer on screen than the real event, which is over in about a millisecond, so you can see them.