The short One-Elevens seemed to actually have better range that the -500 series. The initial BEA fleet were notably short haulers, I believe from London they couldn't get further than Rome. The later, mostly-IT aircraft were better.
Reference above to the USA fleets, which for the initial production took more than half the output, reminds that the -500 stretched model, like all of the Tridents, was never even offered to the FAA for certification. The only ones you might see in the USA were Caribbean/Latin American operators at Miami.