Complex sentence: The car was used until 1950 when State Car No.5 was built, rendering most of the State Cars obsolete; by 1953 State Car No.1 had been scrapped, with the underframe transferred to Norman.
Split into simpler sentences: The car was used until 1950, when State Car No.5 was built, which rendered most of the other State Cars obsolete. By 1953 State Car No.1 had been scrapped, with the underframe transferred to Norman.