without seeing you it sounds fairly good at present. would have like you to have >90 degrees by now but not far off. if wounds are healed and if ok with surgeon, you could go to the pool, aquajog, walk in the deep end (if no pain and allowed as will only be partial weightbearing in deep water), do exercises, such as minisquats, minilunges etc, swim. you may also be able to do some cycling - again check with surgeon
physio sounds like doing a geat job with soft-tissue work, is he/she also mobilsing (fiddling!) around with your kneecap and the knee joint in generally to include good glide and function here? whilst you are still in brace the movement gained will be slower, you should be out soon, then you should make some greater gains.

remember you have had a major injury, and major surgery, so the recovery will be relatively slow, but should improve each week. the knee will also never be 'as it was' and you will have to continue to work on it.

good luck