Rocky Peak Ridge (2)

Whenever anyone asks about time to hike from here-to-there, the first thing anyone wants to know is skill level. So before I ask, here's my basic stuff. I'm 68 but fortunately in very good health, and I have been coming up to the Adirondacks for over 40 years from Cleveland. Here in Cleveland I do 20 minute trail miles (but of course we have no elevation gain to speak of). I have only done this many miles once, many years ago. My typical climb has been around 2000' give or take, and perhaps 7-8 miles. I have climbed a good number of mountains, including Gothic, Saddleback (both directions), Basin, Marcy, Haystack, Gray, Table, Colden, Algonquin, Skylight, Whiteface, Giant, etc. The big ones I did mostly one at a time. I'm slow but relatively steady. I will be attempting RPR in two weeks from New Russia, going in and coming out the same way. So here's my question: I am giving myself 12 hours to do it. My plan is to hit the trail by 7am, which would get me back to my car, naturally, at 7pm. I will have a headlamp with me (though I have never hiked at night), so I feel that even 14 hours can be done safely. Any of you who have hiked in and out on the East Trail, how long did it take you to get to RPR vs the return trip to the trailhead? I'm aware of the lack of water and the need to carry what I need (will have a filter), and that I am looking at 5000' of elevation gain. I climbed Snowy right after Irene, and was surprised at the amount of rocks I had to climb over and around toward the top. I read somewhere that the approach to RPR itself is similar to Snowy. Is that accurate? Any other info anyone might be able to shoot my way would be greatly appreciated. In closing, I know my body, and I know not to get stupid. Just want to have a solid idea of what I am facing going in.