Will the 82-315 key fit my lock?

The 82-315 won't install on your outside handle, unfortunately. You'd have to replace the outside handle with our 82-044 in order for it to work.

That said, I'm also not sure if the 83-314 is compatible with your mortise. I've seen this mortise before, but it was used with a different style handle set entirely. The 82-315 key has a flat tail that inserts into a 45 degree slot in the mortise. If your mortise has no such slot, then it will not work.

The video below shows how our 82-315 and 82-044 work together.