It's a bear!

Early 1920's Small/Small Medium Bore TIS Standard
Bore: .475"-.490" (12 mm-12.4 mm)
Bell: 6½" (165.1 mm)

Prior to the introduction of the Self-Balancing model in the mid-1920's, all of Frank Olds' trombones followed this same general design. This horn is typical of the pattern, but is interesting because it is has a smaller bore than most of the surviving examples (which are typically .485"/500" or .495"/.510" nominal bore with a 7" or 7½" bell). It presents an interesting question in that the serial numbers of the slide and bell sections match, but the size/bore designators do not - the slide is marked "S" and the bell is marked "SM". These would correspond to Olds' "Solo" and "Small Medium" models, as described below (taken from a ©1925 catalog):


In the early 1920's, a trombone this size would probably have been considered on the small side for general use. It would most likely been used as a soloist's horn, where the ability to project over a large ensemble would be desirable.

The case appears to be original, and uses a novel approach to securing the slide; rather than sliding the upper brace under a block and then securing the tubes using a rotating bar, one slides the upper tube under a block and then secures the upper brace with a leather snap strap. I'm not sure what the block at the upper end of the bell half of the case is meant to hold; it does not seem properly shaped to hold an extra crook for a high-pitch/low-pitch horn.

Overall View	Bell Engraving	Braces	Case
	End Crook	Serial Number - Bell	Serial Number - Slide