What are your thoughts on protein, how much, and the timing of that intake?
Currently weigh about 75kg, aerobic exercise 8-9 hours, rising to 10 hours by March, and 12-13 hours from early May. Aiming to be down to about 70-71kg by August but not at expense of muscle.
TrainerRoad just did a deep dive on protein intake:
You and I weigh the same. I see a lot of 1.6g/kg or even 0.9g/lb. I’m sure the coaches in here will give you good recommendations. For me personally when trying to lose and/or maintain weight I’ve found that protein is the key. I will prioritize my protein intake and have all my meals revolve around it. And if you prioritize nutrient dense, whole/real foods then you’ll basically be maximizing your satiety per calorie and have a pretty good body composition. So easy right?! 
I usually end up around 150g/day, sometimes more, rarely less. You put more hours in than me so certainly would need to take in more calories.
As with most things nutrition related. Gotta find what works for you and stick with it!
The Academy of Nutrition and Dietetics recommends 1.2-2.0 gram/kg for athletes, depending on training focus. Generally, that breaks down to 1.2-1.6 for endurance athletes and 1.4-2.0 for strength/power athletes.Aging athletes (50+ years old) benefit from increased daily protein intake (1.6-2.0 g/kg) and larger amounts of protein per feeding (40 grams/meal rather than 20 grams/meal) for muscle protein synthesis, recovery, and long-term training adaptations (Doering 2016). And rather than concentrating protein consumption in one or two large feedings each day, it is better to consume 20-30 grams at a time during feedings throughout the day.
Considering that most overlapping ranges for recommended protein intake across different athlete groups, let’s use 1.8 g/kg per day as the target amount for a theoretical 75-kilogram (165 pound) masters athlete. Provided that this athlete is meeting their total daily energy requirement (protein requirements increase even further during caloric restriction), the daily target for protein would be 135 grams.
In my experince, protein is the macro-nutrient many athletes especially master age athletes at 50yrs and older get wrong and do not eat enough. your body uses carb and fat as it fuel sources, very little from protein. Protein is so critical for recovery and weight management. Spread proetin evenly across the day with meals targeting 30-40g.