I am in process of repairing a 1960's pocket door for my son-in-law. The pocket door is connected to the track via two three- wheel tricycle trolleys. The wheels appear to be nylon and are worn. The wheels have the name "JOHNSON" molded in. The tricycle width dimension is 1 1/2 inch, outside to outside. Johnson Hardware makes new pocket door hardware and when I called them they told me they never made any trolleys greater then 1.o inch outside dimension. The track appears to be steel, steel frame and well fastened to the house framing with a one inch opening with a tapered lip. One side is shortened to install trolleys. The trolley uses a tapered wheel with an OD of 7/8 inches tapered down to a 9/16 dia by 5/16 wide cylinderical section. The trolley connects to the door similarily to the Johnson designs. Has anyone seen this type of trolley design and know the manufacturer? Have not had much luck with internet searches. Replacing the complete pocket door track assembly would be a big task as this house has plaster backer board with a wet plaster finish. Thanks and regards to all.