well, I got the film back today. The negatives are quite dark to look through (which means they're blocking visible light), just like they should be, but with some tests it's apparent that they're not blocking IR light, sweet! So on with the project:-)
pic 1 is a shot without the visible light filter or the IR filter, so it's seeing both. pic 2 is demonstrating the developed negative. It's clear that it's letting almost all IR light through, but blocking most visible light. pic 3 is a shot with the visible light filter completely over the webcam. Pretty scary! My IR LEDs are really bright, I think I need to lower the current in the circuit to get less light so the software can track one reflective point better.