If it is cut off to a 1.5" diameter stump, a bark graft is the best choice and one of the easiest and most successful graft types. Scratch the bark in the area you intend to cut the stump back to and check to see if it is green underneath. I'd probably make sure to cut it below the original graft, no reason to retain any of the original scion as an interstock. If it has been cut in the last few weeks and hasn't been allowed to totally dry out for an extended period, it should be alive. If the scion wood you intend to use is readily available to you, there isn't much to loose in an attempt.

Lots of good videos posted on youtube of bark grafting, as well as other types of grafts. One tip on bark grafts is to shave the edges of the scion bevel cut to expose a sliver of cambium on the sides of the bevel. It can really improve the take percentage and recovery time on problem grafts.

Awesome. Thanks! I was thinking of doing a bark graft in this situation. Do people usually nail the scion into the rootstock or just wrap the scion?

I think you can cut a notch in the rootstock and in the scion to fit like a puzzle? Would that work with the bark method?

For example, picture a diagonal cut with a notch in it on the rootstock. Now picture the same diagonal cut on the scion with an opposite notch cut to fit in/against the rootstock. Then wrap it up.