you could try using filson wax to help it. it is going to look a bit different than it does now, but should help preserve it.

start with a cleaning, use a dry vegetable brush for as much cleaning as possible, maybe a damp sponge for any spots.

you may want to explore using a fabric waterproofing spray like REVIVEX or Scotch guard.
i have never tried using it for this purpose, but it does have some bonding qualities that could really help keep the fibers in place.