I have PRs of 1:17 and 2:54 and am just a few years older than you, so I have some idea of the place you are fitness-wise. The info you provided was helpful.
Although it looks from your workouts as if you could likely run 2:45-2:49, I would say for this first marathon to not go under 6:40 pace (~2:54:40) until at least halfway in, preferably not until 20 miles.
You seem like a sensible person, and of course you know that very few people say after their debut marathon, "I projected my marathon ability from my half marathon time and tempo workouts, and it went really well." Probably well over 90% say the opposite. Absolutely blowing up can really mess with people and even some elites never seem to quite nail it after that experience (Tadese, Bairu). Some will argue it's a good learning experience, but I've run 1:32/1:27 and I've run 1:25/1:35 and I don't fondly look back on the latter as a character-building experience, I look back on it as stupidly wasting six months of work.
You have many more marathons ahead of you and as a debut, running controlled to 20 miles and then ripping the hardest 10k of your life (and it will still be damn hard) will feel incredible and show you something about your ability. You will have a nice low-2:50s debut, and with the splits Ventolin can tell you your marathon ability for your next one this fall ;)
Good luck!