My sister gave me two pairs. She bought them in the States.
I'll ask her where she got them. Maybe I can track down the store and ask them for the manufacturers' name. I went over my sandals with a magnifying glass but couldn't see a brand name. I saw a similar pair here in Toronto but they had no ridges or arch support. I'll do my best finding out where to buy the sandals. I wish I could have been of more help. Best of luck.
P.S. I agree with you - I also think the ridges stretch the toes into a more normal position.