New hinges are probably a good idea. Plastics/nylons, of any kind, can/do deteriorate over time. My own GP Sr. Falcon flies regularly with 40-yr old hinges and I check them regularly. Many of my CL planes are also 40+ yrs old and still flying with original hinges - they also get checked near every flight. The way, though, not to worry so much is to simply get new ones - which you're doing. Good move.