I honestly would change the belt on that mate regardless of the mileage.

The belt change intervals are specified for a reason. Over the the years the materials used to make the belt deteriorate due to oil contamination, wear etc.

I worked as a technician for a Ford dealer a few years ago and have seen the mess when a belt snaps. Not a pretty sight.

The choice however is yours. Change the belt and avoid an even more expensive repair bill or risk it and pray the belt doesn't snap.