I have a Lionel 681 Locomotive with tender, 2671w. I'm pretty sure the locomotive has the white heat stamp, but can't be 100% sure as I know very little about trains. I've learned that most had a silver rubber stamp on it and mine isn't silver at all. The number 681 looks like it was printed directly on it.
Here's an actual picture of it: http://yfrog.com/49681set5j
Thanks for the help in advanced.
Here's an actual picture of it: http://yfrog.com/49681set5j
Thanks for the help in advanced.