Peg,
I had a similar seat in my '48 panel in 1969. You show a pick-up which has a back stop and seat frame on the floor. In a panel truck (and similarly in a suburban), driving from stop is quite exciting on the smooth floor (stopping was not bad, however - you have the steering wheel to stop your body).
Mike's custom seat that you show is not a captain' chair - that is a higher cost option which has arms.
I passed inspection two times (in VA) before it was suggested that the chair be attached to the floor (no joke).
Tim
