I am sure this has been covered before but I couldn't find it.

How can someone estimate the approximate age of a particular straight razor?

I understand that the vast majority of vintage razors were manufactured or crafted between 1850 and 1950 - but that's a big range.

What are the tell tale signs of the older ones as opposed to the newer ones?

And for those who collect, to what extent is age a value determining variable? I am surprised that approximate age is not mentioned more often in the classifieds as I would have thought older blades would be seen as a more valuable collectible.

Thanks in advance for thoughtful responses.

Seth