Fred...
It was kingston, the Royals of that day all had tops that clamped on, the Kingston was hinged, Royal did not use the hinged top until after Saniway folded in 76, also the Saniway attachments are Kingston,,the way I heard it was that the man who started Saniway bought the dies and all from Kingston and manufactured the thing himself,in a small factory in Toledo,the major metal work was outsourced, and it was basically an assembly plant,the original rug tool 1960-1963 was exactly like a Kingston as was the cleaner, I have a Kingston owners manual and they are identical,beginning in 64 until they closed in 76 the Saniway was as the one you have the markIV , it started out with flat wheels and a braided hose, the ball casters were added in the late 60s a nylaflex hose about 73, when the owner died in 76 his wife closed the doors and sold everything off, I got all this from his first distributor Cyrus Fox of Asheville,if I can get a copy made Ill send you an owners manual for both the Kingston and SAniway,I have both versions ,also they had a germ killing contraption that went on the exhaust, I have one in the box if I can find it, hope this info helps Hans