I have to return the 82-080 I ordered by mistake. Mine takes the 3 15/16" not 4 15/16.
I believe the 82-086 will fit, it has the inside lever lower than center which seems to be correct. My worry is that the locking lever will have a square shaft entering the mortice lock from the inside (mine appears to be the same as your 82-218 mortice) but this mortice has a slot at a 45 degree angle.
How do I arrange the return shipping, I realize I must pay for this.