
I would suggest contacting one of the breed clubs for these breeds. Older pups tend to be homed by a breeder by word of mouth when the right home appears (often from former puppy owners of that breeder asking as you are for older pup or adult).
It would be rare for a good breeder to openly advertise an older one, as that to me would smack of rather a calous/commercial attitude.
As Westies especially are very commercially exploited I would steer clear of any advertised as I would always wonder why it was being got rid of. It could have a health or temperament problem, whereas a breeder who has one not up to the grade will bide their tme for a good home to come along.