Complex sentence: Willesden gained the whole allocation of the 260 in 1981; the allocation was transferred to Brentford's Armchair in 1990, using Leyland Olympians and Leyland Atlanteans.
Split into simpler sentences: Willesden gained the whole allocation of the 260 in 1981. In 1990 the route was taken over by Armcahir Travel, using Leyland Olympians and Leyland Atlanteans.