Very cool composition, I love the variety of instruments and what you've done with them.
For a stronger ragtime impression, I'd suggest going for a swing rhythm. As it is, the syncopation is present in the notes, but kinda difficult to feel.
As I'm saying in many of the submissions: my feedback is an expression of taste rather than objective correctness. You know what kind of quality you have delivered here and I'd be surprised if your submission doesn't end up in one of the absolute top spots. Great work!