This very much depends on what is going to happen on completion.
A restoration is intended to save the past and to protect. This will
normally mean a static display is the finished result as it cannot
meet the safety requirement to go to sea.
A replica is used to recreate the feel and general appearance of the
original and can therefore include the modern safety equipment that
is require for it to go to sea.
So, yes, it you have an original by all means restore but if you wish
to experiance what it was like to sail these vessels then it has to be
a replica.
The two do not present a conflict to me providing that it is clearly defined.
Dave M