The two 1970s carriages were due to return in March, but delays with the fabrication and galvanising of the new chassis meant the repairs could not be completed in time, they were instead delivered on May 4.
Foreshore Road was closed to allow a 50-tonne crane to lift the carriages back onto the rails, as spectators looked on to welcome their return.
The two carriages had not been refurbished in 50 years, but have now been stripped down and fully rebuilt at a specialist yard in Rotherham under the expertise of Martin Hudson, Managing Director at Wheelsets UK.
Helen Galvin, Central Tramway's General Manager said: "We are delighted to have the carriages back in Scarborough and back in operation, looking like new.
"We've taken the last four months to do essential work at the stations and we can't wait to welcome passengers back. Martin and his team have done a fantastic job modernising the tramway whilst retaining its original character and charm."
The refurbished carriages have received new floors, ceilings, lights, seats and brakes, as the vehicles suffer badly from weather-related corrosion in their exposed cliffside location – as well as damage caused by seagull droppings.
The project, which lasted four months and required 12 months of planning, began in January when the carriages were removed with hopes of reopening in time for Easter and the return of tourists during the school holidays, but this was postponed by about one month due to engineering delays.
Mr Hudson said: "This has been a very challenging project with many surprises along the way. Unfortunately, there were also delays and difficulties due to current issues with the supply of equipment and services."
Founded in 1881, the Central Tramway Company remains privately owned with the business investing more than £800,000 over the last 12 years on infrastructure improvements and advancements in technology – making it amongst the safest cliff lifts in the country.
Amy Bartle, Central Tramway's Marketing Director said: "Central Tramway is part of the South Bay landscape, we know how important it is for both locals and visitors and we see ourselves as custodians of this historic Scarborough amenity and attraction.
"Our hope is that this work will guarantee the safe running of the tramway for many more years to come. We want to thank our neighbours and friends on the South Bay, as well as regular visitors to Scarborough for their support and understanding while we've been closed.
"We're very happy to be up and running again in time for the busy summer season, the Jubilee celebrations and Armed Forces Day this year."
The historic cliff lift will reopen from Friday May 20 between 9.30am and 5.45pm.