Antique Desk

This is an antique desk of mine, of which I do not have much background information at all. I bought it in Southern California and seems to be in a Spanish Mission / Spanish Colonial style. It's a very heavy, sturdy piece.

At the front and center of the desktop is a copper plate, which is imbedded into the wood. It shows a lion, with letters (not of the Roman alphabet) above and below it.

I would appreciate any information that can be provided either about the desk, style, copper plate or resources for researching it.

Thank you.