I ordered a stock and forend for a 511-A Savage shotgun from Gunparts. They were both made from "hardwood" but the colors of stain are no where close to matching. If I strip the forend and match the stain, what finish do they use for the topcoat ?

It's birch wood. Undoubtedly they used tinted lacquer. Good luck...

Just a guess for what would work to match them up - strip both, bleach them to lightest color and use a dark stain before covering with tung oil.

Velvet oil.You can buy it with the stain in it or clear.It is the best stock refinishing oil I have ever used.

I like the method czech suggested. If they are close in color you may not need to bleach them. Use very dilute spirit stains and apply more wash coats to the lighter wood. Velvet oil is good but you will still have different amounts of color unless stained differently. I like Transtint stains or the laurel mountain pre-mixed.