Salted is $37 to $40 ($29.10 for Amazon Prime members) as a print book, but as an ebook it is $10.99 at Amazon (Kindle), Barnes & Noble (Nook), Google Play Books, and Kobo. Also, leaving the kind of salt unspecified isn't just a problem of "older cookbooks," whatever "older" means.
What I get from this thread, and from the Epicurious guide, is that even if your source of a recipe is not a recent (how recent?) cookbook by a single author who is considered an expert, and who has spelled it all out in the front of the book, there are things you can do. Make the best educated guess you can: use what you have (usually), get the best advice you can get (such as the guides mentioned in this thread), do whatever conversions you need to do.
I resolve that the next salt I buy will not be iodized. I can't taste the difference, but you can never tell whether there may be a supertaster among those you bake for. That's the same reason I use an aluminum-free baking powder.
And egg sizes - that's for another thread.