Well, of course Chuck has an SR-71 checklist! Why wouldn’t he? I actually have a checklist and a flight manual for the Saturn V rocket at home I got from eBay. (That’s right, I am officially coming out as space nerd) It’s really cool actually, because it is set up and reads just like any flight manual from that era would, except … its a freaking rocket!!
I read a really cool book about the SR-71 not too long ago and it had a few checklist items in there where the author explains briefly how the Blackbird works. But I’m suspecting those were probably heavily redacted. Nonetheless, that’s how Chuck ended up with this checklist. And it’s pretty obvious he has lost the Piper checklist a long time ago, so why not replace it with something cool, right?!