Tire tread wear vs inflation pressure

I discovered when I bought my plane that pretty much every aircraft tire
I had ever seen was underinflated. The manual calls for 42psi in the
mains on my plane, and if you can see even the slightest sidewall
squishiness they're down in the low 30's and at the end of a month they're
down below 30psi. Just the result of 1960s rubber technology, I guess.

I keep mine aired up at least once a month because otherwise it becomes
very hard to push the plane back into the hangar over the lip of concrete
and the door track.

However, I've noticed that the treadwear (not all due to me, I'm still on
the tires that were on the plane when I bought it) is greater in the center
of the tire, which on a car tire would be consistent with overinflation.
Are aircraft tires expected to wear evenly from edge to edge?

--
Ben Jackson AD7GD

http://www.ben.com/