If his skeleton is available I think modern tests could determine an age range. I know they are cartilage, but the ears grow continuously, so he would have had abnormally large ears. Carbon 14 dating could probably date him too, as we gain Carbon 14 as long as wee are alive and eating, and then it slowly decays after we die.
The ears are not the only thing that gets bigger with age.
C-14 Dating can only tell us how long ago a living organism died - not its age at the time of death.
Regards,
Interesting idea, of course the drawback would be, can someone go pry open a vault in Westminster. :^) The C14 date would yield a good-sized margin of error due to the recent date, and would only give the death date, as alexander_busek said. There aren't that many parts of the human body that exceed six or seven years of age (the cells die off, to be replaced by new cells). The teeth are an exception, and would seem perfect since the teeth form early in life -- but RC dating on tooth enamel is kinda new, and only works with post-1943 births, due to the elevated C14 levels from (believe it or not) nuclear weapon detonations in the atmosphere. If we're in a similar demographic, we all probably remember those days when we were told not to eat the snow or use it for making homemade icecream (that's usually not a winter activity though). As the instrumentation sensitivity improves, probably dating teeth will become a thing for archaeology as well.