I watched a program a while back about the Old Rhinebeck Aerodrome. One segment was an interview with the person responsible for maintaining the WWI vintage aircraft. The interviewer asked how the team deals with lack of parts. Specifically, he was asked if they used modern materials to replace original parts when they break. He said they try to stick as closely as possible to the original materials and processes. His reasoning was the original design was proven, and changing materials on a given part might transfer structural stress(es) that part was meant to bear to another that wasn’t.