I saw all the pics on AT too! You bag reminds me very much of my colorblock Rambler, also an NYC bag! I have worked on dozens of bags, but that was the driest bag I ever worked on and I really did not fully appreciate it at the time. I would do a lot differently, but it is water under the bridge. If you want to continue only BlackRock and CPR, I would give it a generous app of CPR, wait 2 days during which I would generously buff with a soft towel and horsehair bush. Then apply an app of BR, doing the same. Continue several rounds to see how the leather responds. If it does respond, continue until you are satisfied

Given the products I have on hand, I would apply an app of Obenauf’s Oil, wait 4-5 days. Then dunk again, and while wet/damp applying 2-3 apps of Leather Therapy RC (maybe 12 hours apart), then a few apps of CPR and then Renapur, which I use in place of BR. Buffing like a madwoman in between apps of everything.
Bear in mind these are products I have used, many here use other products I have not gotten around to.
Best of luck and I didn’t say so already,
love that bag

Keep us posted!
Eta - other opinions are welcome