I relate to this 100% jkb, and this is how I have travelled this road. For me, there weren't instances of my behaviour that required restitution in any material sense that I hadn't already addressed at their time of occurrence. I didn't owe money, I hadn't broken anything I hadn't replaced, for example.
But there were all sorts of other things I had done that I was not proud of, not by a long shot. These were instances of me being a jerk and an a$$h**e, not to put too fine a point on it. The self talk that circulated around these actions was really keeping me depressed, a constant reminder of my lack of maturity and refusal to take responsibility for my actions.
The day I quit drinking, I went through a period of acceptance. I accepted that I no longer drank, I accepted that I had done some things I was not proud of, and I accepted that those things cannot ever be undone. My means of restitution was to stop drinking and start doing the right things during this present moment. I made a FreshStart, as it were.
Part of the stuff I learned with AVRT was mindfulness, about how to pay attention to the present to the exclusion of fretting over things in the past that can't be changed, or things in the future that haven't yet happened. The past just is, and the best we can do is to accept that these things happened, and will never happen again.
Part of the oomph I got that let me do this was simply my resolution to quit drinking. I had taken control and responsibility again of my life and I was doing the right thing for the right reason now.
I hope this can help you, jkb. Best to you.