I kind of skipped through all of the posts and suggestions but I have a question for the OP. In your first post you state it's a new battery, did you have this battery draining issue before you put a new battery in? What if it's a bad (new) battery? Just saying.
Yes, the owner changed the battery because of it draining, and it still drains with the new battery.
He purchased the car from an estate recently, so we don't know any of it's previous history. But it is in very nice original condition
