Ah yes our Canadian Robertson bolts and screws used in many Canadian built makes. Canadian built cars in US judging were considered wrong, until judges were proven wrong. Every now an then someone in Forum with a Canadian vehicle wants to know where you find the funny slotted screws for their Star / Durant.
Much prefer Robertson screws doing any woodwork.
Where Are You From? Ottawa Ontario Canada
Do You own a car built by Durant? 1932 614 sedan made by Dominion Motors