When restoring old dried out clock case that have separated joints, what type of glue should be used? Thanks

Go for the Hide Glue Wayne,that's what was originally used to fasten those cases together.I'm sure everyone has their own favorite adhesive that they will recommend to you and there's not a doubt in my mind that they all work well but hide glue was what they used way back when.
Respectfully,Bob Fullerton

Bob,
Thanks much, found a source for hide glue on the internet, and have it on order.