There is no need to change your cadence. Generally, a higher cadence reduces the risk of injuries, which becomes more and more important after age 50.
Your pace is excellent for your age. If you're running marathons, I wouldn't change a thing. If you're running the 1500 to 5000, you can possibly gain more speed and especially more kick at the end of your races by changing your hill sprints as follows.
Do the following DRILL. Let me emphasize, this is a drill, it's not sprinting or running. Find a steep hill. "Steep" is steep enough that you could not run down it at an all out sprint. Reduce the time of your sprints... 45 seconds is way too long for this drill and will cause you to drop back into your normal shuffling stride.
Don't start from a standing position. Roll up the start with a slow jog to reduce the risk of injury. Run 15 seconds powering up the hill. Lift your knees a little more than you normally would. Push off a little more than you normally would. But other than that, it's an all out effort.
You will NOT be as fast as you would be in your normal hill sprints. That doesn't matter. You'll be tempted to revert to your normal form, especially as you get tired. Don't. Have the discipline to stay with the slight knee lift, slight push-off, powering motion. Remember. It. Is. A. Drill.
Mark how far you get with a stick or something. Walk back down. Take at least 90 seconds of recovery. Do 8 reps if you can. If you're short of your mark by 5 meters or so, the workout is over, even if you only did 5 reps.
Once you can do 8 reps without slowing, you can increase the time to 20 seconds.
Do NOT run back downhill. Walk or slow jog and wait the full 90 seconds before the next rep.
This drill 1) increases range of motion in a lower-risk movement than level ground. 2) Trains the knee to lift higher 3) Does some other stuff that's with the trailing leg that's too long to go into here 4) Boosts metabolism and testosterone levels. (It's called the Sprint 8 or SIT (Sprint Intensity Training.)