With better lighting and the hints from the guys on this thread, I think it's been nailed down.
Near the bell joint the slide clearly says SYM 5356. Bell serial number is 5095. So this appears to be a "Symphony" model Olds, and if the serial number research is correct, it dates to 1924. I can't find any pics of this model, and it doesn't say Olds or any branding on it. Just these SYM and s/n stamps. Indeed it does have the S bend Andy described and doesn't seem modded for a lefty in any way. Rotor body is stamped 95.
9" bell
Dual bore slide is .508/.533 by my measuring
Small mouthpiece shank
Stampings.
IMG_4978.jpg
IMG_4979.jpg
Offset for the thick-necked:
IMG_4980.jpg
The trigger mechanism: Long, hinged bracket hangs from the top of the bell brace. When actuated by pressing forward, it pulls a string through a guide tube that loops over the top of the rotor and rotates it forward via an attachment point. The string is broken. I'm not sure what it would take to hold this design without always having the trigger pressed. I'll play around with it.
IMG_4982.jpg
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