I think 10k in May is feasible. Ask your physio about structured braces for your leg rather than simple supports that work by compression. There are ACL specific braces which can be worn before and after corrective surgery and your physio may feel that one would be appropriate for you to use during running. You can get along pretty well without your ACL most of the time - but brace yourself (no pun intended) for the likelihood of requiring a knee replacement before you reach your dotage. (I'm basing that on the info you've given regarding the trauma and the cartilage damage). Keep your quads strong and maintain length in your hamstrings.
Then it's probably time to go shopping Clive. At a year old your shoes are probably not providing the support you require (depending on your mileage over that year and your weight). I'd say you wouldn't develop a stress fracture on the distances you are running - but if you pronate and your shoes are knackered then it's more possible. Treat yourself to a new pair now and put more pairs on your birthday and Santa list.