I could find no evidence under either capitalization. DCDuringTALK 03:42, 12 December 2010 (UTC)
Anecdotally, in the early 1980s in Singapore, Indonesia ports, 'brass monkey' was served at bars catering to sailors. The constituent varied between the ports, but was generally high-proof unsweetened flavoured alcohol, usually including star anise. No citations, but a couple of memorable shore leaves... - Amgine/talk 17:21, 12 December 2010 (UTC)
What memories about capitalization have survived? DCDuringTALK 19:52, 12 December 2010 (UTC)
Probably "spend it while you have it" :)Equinox◑ 22:04, 12 December 2010 (UTC)
Only one citation (the one mentioning liquor) makes it clear which of the 3 senses might be involved. The others would be consistent with either beer or a liqueur, possibly even the cocktail. DCDuringTALK 11:06, 22 December 2010 (UTC)
1992 Summit Books (New York): Only the liquor comes in a bottle. The beer so far as I can tell is actually a stout provided on tap at only the Sail & Anchor Pub Brewery in Fremantle, Western Australia.
1993 SPIN: this one I guess isn't certain, though it does have capitalization going for it and other brands like Snapple are named.
1994 Norton & Co. (New York): Olde English is a malt liquor by Miller and Cisco is a low-end fortified wine from New York, so this is consistent with the description of Brass Monkey as "inexpensive".
2007 Bancroft Press (Baltimore): I added the use on page 147 indicating the liquor.
2008 Mercer U. Press (Georgia): Liquor is mentioned elsewhere in the book as consumed by that character, as well as brand names like Kentucky Fried Chicken.
Thanks: the explanation provides a necessary record. The cocktail doesn't require an RfV, does it? I forgot whether I saw cites for it when I was looking, though I assume I did. DCDuringTALK 15:15, 22 December 2010 (UTC)
Personally I don't think it requires an RFV, as there were many more quotations in the lowercase, and even a few recipes. Of course, we're always welcome to RFV any doubted term. DAVilla 05:27, 23 December 2010 (UTC)