Titch, that's the problem with the internet sometimes. It obscures previous information and just presents the new consensus.
I have plenty of old sources and was taught it was, "Here. Here." as in 'over here, this person here, I agree."
You would use, "Hear. Hear." in a situation such as, "Hear ye. Here ye." when announcing something.
But, the term for agreement is, "Here. Here."
The internet is not the only source or even the best source for historical word use.