It's actually pretty much exactly what you see in piano sheet music! These are just fingerings to help the first violins execute that scalar run.

Note that, in contrast to piano fingerings, 1 indicates the index finger, 2 the middle finger, etc.

The next question may then be why the fingerings are only given for the first violins. The run is the same in all voices, so I assume the fingerings would be, as well.

PS: Great piece!

It's actually pretty much exactly what you see in piano sheet music! These are just fingerings to help the first violins execute that scalar run.

Note that, in contrast to piano fingerings, 1 indicates the index finger, 2 the middle finger, etc.

The next question may then be why the fingerings are only given for the first violins. I'm not entirely, sure but the run is the same in all voices, so I assume the fingerings would be, as well. Or perhaps the run just happens to be placed more easily in the other instruments. (But I'm no string player, beware of this explanation!)

PS: Great piece!