I think we are getting our definitions mixed up here; a replica is an exact reproduction of an object by the original artist, or in this case manufacturer. A good example is the reproduced Yaks at Orenburg; these are true replicas. The majority of warbirds flying today are reproductions or reconstructions incorporating original components, if you take the exact meaning of the word "replica" literally, because there is little in current warbirds that is from the original airframe - necessary for certification reasons.
Because of the fine standard of workmanship and the adherence to techniques and materials used at the time, some airframes can be described as "late production" models, such as the work of Desmond St Cyrien, who expertly crafted a number of fine reproductions of Sopwith aeroplanes in the 1960s, but concocted a story about them being originals that were 'discovered' in an abandoned barn in France. Even Tommy Sopwith himself, on examining St Cyrien's Sopwith Pup (now at the RAF Museum) claimed that it was exactly as Pups were built by his factory. The work of The Vintage Aviator or what Glynn Powell is doing for the de Havilland Mosquito come under this description, as well.
While some of you might decry the decision to preserve a Tornado F.3 in a British museum, but lament the fact that there are no Westland Whirlwinds (fighters, not choppers) surviving, at least the MOD has the foresight to recognise that today's airframes might mean something in years to come; they don't want to be making the same mistakes as their predecessors. Not everything can or should be saved because of space, cost of maintenance and upkeep etc, but starting with maybe one or two examples of things in proper care is a good thing.
It saddens me when historic ships are disposed of; the UK has an example in the Trafalgar era ship-of-the-line Implacable, which was sunk off the coast of the Isle of Wight in 1949 by the Royal Navy; an absolute travesty since it was originally a French vessel that took part in Trafalgar and was captured by the Brits - how could such an historic ship that survived for nearly 200 years be sunk? Protests from the public saw the clipper ship Cutty Sark spared from a similar fate. Implacable's stern facade and figurehead survive at Greenwich as a reminder of our lack of foresight, although the Falklands veteran HMS Plymouth is under threat now; do we never learn?