I agree with stoneyboy that there is a fair chance that those old locks (or at least some of them) will be fixable. There is a high chance that some of them won't be fixable. Fortunately advancements in metal latches, and even door hinges have made it easier than ever to find classic looking door accessories. Don't think that you cannot still buy iron door parts that match the decor of your older home, just because 90 years old. I would investigate both replacement and repair and decide on a strategy that suits your needs. You may be surprised at what you find.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!