i tried a few strains of terrier about 18 years ago. i had some nice dogs off parkes and my mate at the time kept and worked only parkes strain. and he new john very well. my mate loaned wendy bell a black parkes bred terrier called blitz ,a real over hard dog, anyway wendy bell put this dog to some of her bitches ,producing some handy dogs. i had a red bitch off parkes ,very border lookin. she didnt enter till she was 3 year old, but when she did she was very hard,overhard. and within a year she had face like donner kebab. and could only be used for digging once in a while. personaly for me