water flow regulators for radiators

freezinme bum

Does anyone out there know where to find 1'X 1/2" black iron "T" regulators for old cast iron radiators? These particular T's have a cone type apparatus inside that re-
gulates the flow of water to and from the radiator. I have
an old home that was built around 1900.I have a gas boiler that heats the water goes through pipes into my radiators. The system is now in need of repair and this is
an old part to be sure. The metal tag on the T was imprinted with SUP(arrow pointing up)PLY followed underneath this by MO BG(circles around these letters)FLOW
patent #9024832 The part with the arrow pointing up is the 1/2". If I can find several of these T's to replace the existing ones I can salvage the existing system which
I really love. Radiators work so nicely to heat ones home.
I was told that these parts were made up until 3 years ago and am hoping someone has some somewhere perhaps up on a lonely shelf waiting to be placed in my home?! Any information will be greatly appreciated. Oh, a price would also be good to know...Thanks so much for your time and efforts.............