Thanks for all the replies. I have followed up on them. Engravers' Gothic has the 3 elements missing in Copperplate Gothic, but unfortunately lacks the Copperplate-style serifs. It turns out that both Engravers' Gothic and Copperplate Gothic were released by the American Type Founders Company in 1901. I think Engravers' Gothic pairs up well with Copperplate Gothic.

Here's a link to a page with photos of the original document. (If the link doesn't work, try Vintage-1904-Abercrombie-Fitch-New-York-LETTERHEAD on ebay.) If you scroll way down, there are more photos.

http://www.ebay.com/itm/Vintage-1904-Abercrombie-Fitch-New-York-LETTERHEAD-Ezra-Fitch-Lake-Mohonk-/161008814537?nma=true&si=T82zTNys9mVz%252BbQ2JSTuVcg4OoA%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Also, the letters seem to be raised. Apparently engraved, although I can't see any sign of it on the back of the page. I'm looking to see which engraver might have done the work; the Manhattan Engraving Company seems like a possibility.