Now is a good time to replace that cottered crank with a cotterless crank. I personally haven't done one, but read up on it and its no problem as long as the replacment has the same threads as orginial. Peugeots require French Threads. Most others are English. Just a matter of removing the crank and bearings and replacing with similar chain rings and crank and updated cotterless crank. I have a peugeot that would love to do that with. Everytime you regrease the bearing in the crank the cotter pins should be replaced. That extra expense , plus a less efficient design is reason enough to lose the cottered crank system. If you had a parts bike or access to one it wouldn't cost anything. Asking a shop to do it would be big bucks