The knee is definitely improving. I don't feel it at work and rarely whilst walking around. Also at circuits last night I managed squats, lunges and a few single leg squats with no ill effects. I even ran for a few minutes, very slowly, only way there. I didn't feel any patellar or quadriceps insertion pain. Testing it for 500m is not quite the same as undertaking a 50km event but it is a start.
The swimming is improving in outcomes even if not in style. This evening I had time to do 1500m session and didn't do any drills. I focussed on restarting lengths with as little pauses as I felt I could cope with and kept my pace very comfortable whilst moving. As I tired it became quite clear that my breathing slowed and things fitted together as I relaxed. Probably my technique became shoddy but I was very pleased to find that I averaged 3:35min/100m for the whole activity.