Fannie's Books and Derivatives
"Useful" is rather subjective. If you clarify what you mean by useful I can likely clarify and improve my answer as well.

One thing to keep in mind when using old cookbooks and recipes is that terminology changes a lot over time. You may have significant difficulty translating ingredients to their modern equivalents. You also may not be able to easily find the ingredients once you do translate them. A good example is this question.

Another thing you may need to be aware of is how much our knowledge has changed. You'll likely encounter a lot more misinformation than a more modern cookbook. 

If you enjoy the extra work involved, then sure why not get the old ones. If you have trouble translating a recipe, you can always ask here! :)