Be aware that all aircraft flares are 37 deg not 45. Based on 43.13 is seems like you could replace it in 2 pieces.
From AC43.13
Repair of Metal Tube Lines. Minor dents and
scratches in tubing may be repaired. Scratches or nicks
not deeper than 10 percent of the wall thickness in
aluminum alloy tubing, that are not in the heel of a
bend, may be repaired by burnishing with hand tools.
Replace lines with severe die marks, seams, or splits in
the tube. Any crack or deformity in a flare is
unacceptable and cause for rejection. A dent less than
10 percent of the tube diameter is not objectionable
unless it is in the heel of a bend. A severely-damaged
line should be replaced; however, it may be repaired by
cutting out the damaged section and inserting a tube
section of the same size and material. Flare both ends
of the undamaged and replacement tube sections and
make the connection by using standard unions, sleeves,
and tube nuts. If the damaged portion is short enough,
omit the insert tube and repair by using one union and
two sets of connection fittings.