We recreated a Theater Orchestra from members of the Merrimack Valley Philharmonic Orchestra. It consisted of 11 pieces: 1st and 2nd violins, viola, cello, double bass, flute, clarinet, 2 cornets, trombone, and percussion.
Just a few comments to add to the mix.
The music you played, when was it dated from?
All of the music we played was vintage 1910's and 1920's. I got most of the arrangements on Ebay, including a few from Rick Benjamin (founder and leader of the Paragon Ragtime Orchestra). The arrangements came with varying instrumentation: sometimes there were 2 clarinets, sometimes a horn or two, or a bassoon. Makes me understand where the picture of the guy with all those different instruments "came" from.
Btw, I have a picture postcard of a Theater Orchestra from Haverhill, MA called the Pentucket Orchestra. I am having a problem getting a good scan of it, or I'd post it here. The personnel consist of (left to right) flute, clarinet, double bass, violin (conductor?), percussion (playing a "Contraption", the ancestor of today's Trap Set), cello, violin (viola?), another clarinet, trombone, and cornet. The trombonist's instrument bears a striking resemblance to the "The King" instruments of the 1910's with a Low Pitch tuning slide and about a 7 inch bell.