Original sentence: Production Austin-Healey 100s were finished at Austin's Longbridge plant alongside the A90 and based on fully trimmed and painted body/chassis units produced by Jensen in West Bromwich
Edited sentence: Production Austin-Healey 100s were finished at Austin's Longbridge plant alongside the A90 and based on fully trimmed and painted body/chassis units produced by Jensen in West Bromwich — in an arrangement the two companies previously had explored with the Austin A40 Sports