Normal Shutter Curtain Aging or Problem? Pentax KM

These are the shutter curtains on my Pentax KM. Currently there are no pinholes but are these marks going to become a problem? How would I check for them on an SLR? Is it better I get a shutter curtain replaced? Will these become a problem in a couple months to a year? There is some depth on some of the dotted streaks.

Or is this normal Aging and I shouldn't be worrying about them? For some reason, other cameras seem to have super smooth shutter curtains.