Hmmm, realistically, I'd say I would probably still be alive at the age I am, barring the conditions of the era changing things at the small scale.

The only injuries I've had that were life threatening would have been within the capabilities of being taken care of even in more primitive conditions. No major arterial bleeds, no organ injuries or that kind of thing, just severe enough wounds that without a little help, I would have bled out.

Illness wise, it's a guess at best. Vaccines prevent most of the really nasty viruses, so how can I tell if I might have caught one of those? I had measles as kid, and it didn't kill me, nor did chicken pox. The one bad bout of bronchitis I had would have resolved without antibiotics, though I might have been more open to opportunistic infections along with it back then.

But, I wouldn't have had the same life either. Most of the bad injuries were doing things you wouldn't do back then. Bicycle injuries, in particular, might have an equivalent in horse riding, but how close? The fights where I got cut would have equivalents, and I didn't have antibiotics with those, so maybe I would have been fine back then too.

What I am confident in saying is that I would have probably killed myself after my first bad back injury. Unable to walk, little access to pain control, no knowledge that I could recover most of my mobility, I likely would have taken myself out rather than just strongly considering it like I did in reality. So maybe I wouldn't have made it to forty at all.