I've been working on pulling together the story behind the writing of "Bear Down Chicago Bears"--a mystery of perhaps less significance than, "What happened to the WMDs?" Still, you work with what you got.
Along the way, I called the song's current publisher, Mark Spier, of Larry Spier Music, in New York City. He says he's getting lots of requests for the sheet music. Alas, there is no currently published sheet music. So his firm has made a PDF copy of the 1941 sheet music and is selling it online. In the 10 days since the Bears beat the Saints to get into the Super Bowl, Spier has sold 200 to 300 copies (including one copy to me; Dad, it'll be in the mail soon). The first thing I learned from the sheet music, beside the Bears' 1941 address (37 S. Wabash), is that the song is to be played at a "bright march tempo."
You can buy the song from Spier here (it's three bucks; the company is selling several other Bears-related musical items, too). If you're not satisfied with a virtual copy, I found at least one copy of the 1941 original for sale on eBay (the seller has timed it so that the auction will end near game time on Sunday.
One last thing: The graphic on the "Bear Down" cover page: It looks familiar; it's looks similar, in some way, to Chicago Cubs scorecards, which always seemed to have an abstract quality to the cover art (that's the 1941 scorecard here, part of a great online collection assembled by a "die-hard Cubs fan" (poor soul). I wonder if the same illustrator worked for both teams?