“The next most valuable thing you would bring along is what is in your head ...”
Probably the MOST important thing. The pot, fire making tools and knife were around back then. Although good Bowie knife would be a lot better. But even basic knowledge would be helpful (as posted above - bathing, washing hands, clean hygiene, etc.), and of course even more knowledge such as steel fabrication, natural medicine, etc. would get you even farther.
I think it is the hippie on that “Dual Survival” show that says something like “The most important survival gear is what is in your head. And it’s extremely portable.”