Wait... so it's your DS's responsibility to ask the teacher for the papers that the teacher already agreed to send home to you? Which is the responsible adult: your DS, or the teacher??

I don't think you need to waste time defining a 504. He should know. If he doesn't, he'll find out soon enough. I second the recommendation that it's time to write to the 504 coordinator instead, with the following points:

- DS is currently earning a C in Geometry
- DS's teacher has stated directly to you that the reason is because DS's scores are degraded for handwriting and punctuation
- This is in direct violation of the 504.
- You have asked for test copies to validate, the teacher has failed to provide them, and when asked about it, transferred blame to DS.

And ask for immediate intervention to resolve the issue.