I just had my first, will be amhr/show pony registered, a flying w bred mare to a 100 percent arenosa amhr/shetland stallion... colt is loud red and white tobiano/ sabino... couldn't be happier!
a google search for Arenosa or Seth Thomas and the word shetland in quotes
"arenosa shetland" or "Seth Thomas shetland" will turn up lots of breeders of double registered stock. I like the look, and i like to look!