It's a bear!

Engraved Self-Balancing
Bore: .495"-.510" (12.6 mm-12.95 mm)
Bell: 7" (177.8 mm)

This horn is a fairly average Self-Balancing from the mid-1930's (slide s/n M71xx; the bell is only marked LM). It does have some very nice engraving on it, though. Although the slide and bell fit together just fine, they don't seem to quite "match" from an aesthetic standpoint, so I think this might be a parts horn.

Overall view	Bell Engraving	The Bear	Back Side View