All the ones I've seen straight out of the box look like their simply stained with no further effort. What you've done sounds great. If you wanted it to be super durable, use polyurethane (I don't like that look though--I go with tung oil).
It's not a bad idea to put two coats of poly under the buttplate and on the inside of the stock. Thats how mine is set up and it ran flawlessly at the M1A match at Camp Perry last year when we had to use snorkels during the prone stages.