A fellow posted on a similar thread a year or two ago. He had tried it. There are 2 problems. First, the wonderful fumes that are given off are toxic and one of the chemicals causes cancer. The other problem was that by the time you get rid of the case, acid, separator plates, ect, you don't actually get that much lead out of a standard car battery.
Linotype is pretty much a thing of the past. Modern printing presses don't use it, and what was out there has pretty much been scrounged years ago. You'll still come across a guy once in a while that has some stashed in his garage, but he usually isn't willing to part with it. If he is willing to part with it, he usually want's more for it than if you went out and bought commercially made bullets. The same holds true for tin. I've been told by "older" guys to go to scrap yards and ask for "block tin" among other things. This was used in refridgeration coils at one time, but was pretty much replaced by cheaper aluminum 3 or 4 decades ago.
Your main source for lead these days my friend is used wheel weights.
If anyone has any suggestions besides that, I'd like to hear them. I don't want to hear about linotype, or block tin. I've explored the availability of both, and the answer is, they're not. Scrap dealers do still get lead roof sheeting in every once in a while, but it's not hard enough on it's own......great for the black powder guys of course.