This is perhaps the biggest problem with retrobiking, insofar as it limits the lifetime of your retrobike if you want to keep it period correct, or even original.
Sorry to hear of the OP's accident, and I am of the same mind regarding lightweight aluminium retro parts. Earlier this year I re-fitted the original (and barely used bitd) Avenir 185 g alloy bar to my main retro bike, simply to get back to as close to original build for my 1996 DBR Apex as possible. All seemed fine until 20 km into a 50 km mtb marathon race, when a creak started from the handlebar area. Back in the day, I recall everyone's bike had creaks under load after a year or so of use (cranks, bottom bracket, handlebar, seat post, etc.), so I didn't think to much of it. When I got home, after showing and getting some refreshment, I decided to check out the creak. Expecting to a bit of grit to fall out of the clamp area, I removed the bar, and to my horror I discovered a large crack running around 90% the circumference of the bulge of the bar! I nearly fainted at he thought of how hard I took some really gnarly rocky downhill sections, and how close I must have come to a catastropic accident...
From that day on, I have been really paranoid about all my aluminium load bearing parts. When something develops a click, I remove the part, clean, inspect for cracks, refit and if the clicking persists, the part gets retired.
I know also try to use only steel stems, seat posts, and bars. Weight savings from using aluminium are marginal for those parts, and steel is virtually immune to fatigue in this context. Titanium I will use as a second best, but steel gives me absolute peace of mind.