Biewer History has stated that the Biewers had been breeding and showing Yorkies for 20 years when they produced the first tri colored pup.
They continued to breed for this particular color combination for years.
Are you saying the Biewers.. were breeding in other breeds?
Or are you saying unscrupulous breeders after the Biewers,
over the years may have mixed in other breeds?
If your suggesting the latter....... that would be the case with many many breeds.
The BTCA clubs history page.. suggest the same ,the offspring was produced from two of the Biewers, Prized Yorkshire Terriers.
And as for you contacting anybody back then... your offer was to help arrange testing with Mars.
You ended your letter with
" if you have any questions, feel free to contact anyone of the board members"
However, I don't see how that has anything to do with the thread or discussion