Craig, I would go to a good store like TAP Plastics and pick up some quality epoxy. It's stronger than the wood, so you will have a good repair, just make sure you get it well into the broken area. You will need to use something like your bottle jack to push the wood back into place. A piece of wood or metal to distribute the clamping force. Put a couple of sheets of wax paper or plastic between the repair and the piece of wood that distributes the load, otherwise, you'll have a new addition to the bottom of that section.
Talk to the people at the store, and ask questions about the right epoxy to use for temperatures in your area, and to learn what additional supplies you'll need. Measuring cups, mixing cups, etc. They will probably have a good idea on the best way to get it into recesses of the break.
There are also glues that would be effective. Resorcinol is one that is widely used in boat building. Perhaps this might be a better choice now that I think about it. It's widely used in boats, and I suspect not as fussy as epoxy. There's a rumor that we have a couple of wood workers in the group, so let's see what they say.
Talk to the people at the store, and ask questions about the right epoxy to use for temperatures in your area, and to learn what additional supplies you'll need. Measuring cups, mixing cups, etc. They will probably have a good idea on the best way to get it into recesses of the break.
There are also glues that would be effective. Resorcinol is one that is widely used in boat building. Perhaps this might be a better choice now that I think about it. It's widely used in boats, and I suspect not as fussy as epoxy. There's a rumor that we have a couple of wood workers in the group, so let's see what they say.