
If it was my WFT, I would try stripping some on the top coat out ,there will still be some puppy coat, which has to come out to allow the adult coat to come in, best advice is to take your terrier to a groomer who hand strip's, once clipped, it takes a long time to come back in the proper texture, terriers if not shown are usually clipped, I strip all the terriers that come into me for grooming except for 2 oldies!!
They may use a stripping knife also, not so keen on that either, breaks all the hair! :-(