jw4413,
You have narrowed it down pretty well with the new battery and alternator.
Both of these items can cause what you describe, but your clues say it must be something else.
With your well fused '59, the procedure would be to pull fuses, eliminating circuits, until the drain stopped. The circuit that was pulled and killed the drain would then be put under a microscope to find the location of the bare wire, or grounded device.
A small automotive lamp in series with the negative post and the battery cable (taken off) will illuminate when current is passing through it on the way to the short. When you pull the fuse on the circuit that has the problem, the lamp will/should go dead.
A VOM meter can be used in lieu of a light bulb. I think the setting would be DC amps.
This is sort of a overview of the process, and I think you will get the idea. It's a process of elimination using the fuse panel. Good luck.
Stuart
