Humidity and Ukes

I have an old Koa Uke , a cheap one, it's the one I play the most,it hangs on the wall next to my computer. It keeps sounding better and better. The humidity here goes from 10% to 60 or more. Now ,bear with me and tell me if this makes any sense. Old ukuleles like Martins and others were never humidified, they went through variations in humidity for 100 years. Is this a big part of the reason they sound so good ? My cheap uke has been hanging unhumidified for years and has no cracks , and it sounds better than ever.
My vintage Martin which is about 80 years old was never kept humidified until I got it.
Will my Martin keep getting better and better if I dont humidify it? I'm wondering if cracks in ukuleles is just inevitable in some particular pieces of wood and would happen anyway humidified or not?

hmmmmmmmm
it is a matter of do you want to risk it?
I keep all of mine around 40% humidity, always and have found that it is just time and playing that make a difference. I believe that humidity is a key in it sounding good, it wants to be in the 40% range. Yes there are tons that made it a really long time with out cracking but those are worth more becasue they are the lucky ones that made it as long as they have.

Tim and Bill both make great points. Avoid rapid changes in humidity and temperature at all cost. I've seen old Martins with cracks and I've seen other vintage ukes that still look great despite abuse, the particular piece of wood that comprises that particular uke has alot to do with it. Some ukes are doomed to crack because of some unseen fault in the wood, other ukes might be extra tough because of the particulat tree/wood that they are made of. I've noticed that any particular species of wood doesn't necessarily have the same weight or density with others of it's same species. This can be really noticable with the necks we sell, some area little heavier than others but they are the same dimensions and same species of tree. Whether this is due to the environmental conditions it grew under, the soil it was grown in or even the drying method used after it was cut, it's hard to say.