gunwale molding

I would appreciate hearing from anyone who has replaced their gunwale moldings as sections of mine are badly worn. Is it nececcesary to replace the whole length or could only the worn section be taken off and replaced? (They seem to be sold in 6'sections) My Scot is #367 and over 40 years old so I guess that a note to the builder would probably be the best bet unless someone else with an older Scot could give me an answer. Thanks for any advice on this matter.