There are a few different thoughts on using tyvek, one is try blowing air through it and see how well it "actually" breathes, then try it with water from the inside to see how well it "actually" lets moisture escape (not!) The priciple behind housewrap is okay in theory but in reality doesn't work. Your house was built almost 90 years ago with no wrap whatsoever and look at the boards no or very little rot. If it had tyvek over it I could almost guarantee it would be rotten. Unless you make your inside vapour barrier as perfectly air tight as possible you will end up with condensation forming inside your walls with no escape. When I first started building it was the rage now engeneering firms recommend against it as it is the worst thing to do for your house in this area. If your interior vapour barrier is properly done, once the wall cavity equalizes with the atmospheric pressure no water vapour can be blown in as there is no place to blow to. If you don't have a good vapour barrier I believe your better off with building paper and let your house breath.