I too have looked for information on physical recovery rates without success. Alcohol can affect nearly all of the body. The liver bears the brunt of it, but is the organ which has the greatest ability to repair itself.
But, I would like to suggest that there is not much to be gained going down this path. It is certainly worth asking for urine/blood tests to see if any medical intervention is required. For instance, there are drugs which can assist liver function if required, although it's surprising how much abuse it can take before irreversible damage occurs - as long as you let it recover! It's also worth having the tests if it will put your mind at rest.
After being tested and told 'No permanent damage if you stop drinkink NOW' I asked myself the question 'Why do I want to know how long?' I am going down the AF for life route so the question becomes irrelevant to me. It will take as long as it takes.
If you are considering a period of AF, followed by a return to controlled drinking then I think you would be better off asking others in BE what they think a suitable AF period would be. Perhaps the Cutting Down thread could be of use. Just be wary of the empowerment trap i.e 'If it takes x days to repair the damage, then I can have y pints next Friday'. You know where that one goes, I'm sure.
Or is there some other reason e.g. how long before I can start training for a marathon? You could always ask your GP, but given your age and fitness then, unless you have some other medical problem, you'll probably get an automatic 'no probs - carry on' response [sorry doc].
One last thing: I saw the word 'diabetes' mentioned. I have Type 2 diabetes and have had a good deal of success in managing it. So, if the worst comes to the worst you can get advice here on that as well! Fountain of knowledge on all medical problems me, EXCEPT FRIGGING ALCOHOL PROBLEMS!!!!
Anyway, no answers but something to think about I hope.