The difference in the diagrams doesn't look like much, but trust me, it makes a big difference.
What I thought was wrong:
The very end tips (P3 on the diag.) of 3 and 4 and the associated membrane are missing, but the joint is still there.
What is wrong:
Membrane, P3 and the joint are gone completely on both fingers, and the ends of P2 are are exposed to the air. It's not shown on the diagram, but P2 on the sheathtail is 70% of the length of the 3rd finger, and 50% of the 4th finger. Losing these bones would reduce the wing size by about half. The vets might be able to save the wing.