Here's a photo of an original 1680 boiler with complete fittings.
It was in the train set with four streamlined cars painted green. The tender, which I've already sold was the one in this photo.
This was an accidental acquisition with some prewar Lionel that I bought. The engine was such a mess that I'm selling it as parts. The motor looked good but the reverse mechanism was destroyed. NWL, does yours reverse ?
With much difficulty, I got the motor running forward only. I couldn't find the wire to the field. Finally found out from a friend that one side of the field is wired directly to the pickup. So I need to find a buyer for a forward only motor. here it is - runs nicely.
Your 1680 is one of the 1937 versions, as its trim is polished copper/brass. My 1680 has all of the trim on it, it is just painted gloss black, as is correct for 1938.
My engine has the proper Gilbert era drum reverse unit on it and it functions perfectly. Your engine would have had the earlier Chicago era pendulum style reverse unit on it (I can see the remains of it in the photo), which did not always work well.