There's a great website for researching wooden propellers...http://www.woodenpropeller.com/
They have lots of info on identifying older props and even some value info.
I've seen a number of them in antique markets and I don't recall ever seeing one for less than $300.
Many wooden props were replaced by metal ones back around WW2, and these may have come from some such requirement to upgrade for safety reasons. I know that experimental (homebuilt) aircraft are still allowed to use wooden props but there's probably not a lot of demand for them... and if there's the least nick in them they have to be scrapped.
Whatever you do, DO NOT refinish them.. Don't sand and re-varnish them as that will kill their value to collectors, and definitely do not modify the center hub to mount a clock.