George,
I would have a go at cleaning it first, rather than replacing....
I have had good luck cleaning headlinings etc with my "secret" recipe, well it isn't so secret now......
mix up in warm water some floor cleaner and a little laundry detergent.
I find tha ASDA floor cleaner (Wal-Mart in the USA) and "Persil" seem to be the best.
Arm yourself with a soft toothbrush and a small sponge....
Wipe on some of the brew with the sponge gently scrub with the sponge and or the toothbrush and then wipe off with a tea towel or other linen cloth.
Don't soak the lining and do a small patch at a time.
You may have to go round a couple of times
Don't do what I did once which was to clean a headlining in the washing machine (Wife was out :twisted: ).
Boy was it clean but it shrunk by about 20% and it was on cold, gentle wash for woollens.
HTH
Malc