Dean,
That's a very fine plaque you've found, an excellent example of detailed hand-carving. Judging by the looks and patina, I'd say your time-estimate is close, roughly a hundred years old - give or take ... I'm not certain of the wood, though, it does look like walnut, but perhaps something a bit softer?
If the eagle isn't applied to the laminated base it makes the work even more impressive. From what I see of how snug the legs and claws lay, it very well may be carved from a single, laminated board. Also look especially close where the wing-tips overlap and meet the shield.
The eagle is a classic, it has a great overall shape and more than enough detail to let us know that this woodworker was a top-notch pro.
You may like to try this: thoroughly brush off dust and debris with a clean paintbrush. Using a soft old toothbrush apply a mixture of 1 part turpentine to 3 parts boiled linseed oil to the entire unit. Let set 24 hours, you can then buff the smooth surfaces with a soft cotton rag. Be careful of the rougher surfaces as the rag may tend to fray and leave unsightly cotton fibers behind.
You might also choose to use a strong, thin mounting wire if you're going to hang it on a wall. You could also stand it upright in one of those sturdy devices used for oversize porcelain plates and chargers. I'm 100% sure your new eagle will bring a touch of class anywhere you decide to display it.
Congrats on your outstanding new find and thanks for letting us have a look.
Best!
Bill
