The AB-952 mast was built for the Canadian Marconi Company by Espey Mfg. & Electronics Corp. I was fortunate to find one in good shape on eBay a few years ago for $100. I later bought the reflector attachment and guy ring from Fair Radio Sales. The reflector attachment offsets the antenna and makes it harder to install, so I made an adapter and guy ring that keeps the antenna centered over the mast and makes setup easier.
The adapter is simply a short 1-1/4" pipe nipple screwed into a floor flange. Six holes were drilled through the flange and into the inner areas of the top of the mast tube. The tubing holes were tapped for 6-32 screws which secure the flange to the tube. A 1-1/2" floor flange is placed upside down over the 1-1/4" flange with a piece of teflon sheet in between serving as a bearing. Three 1/4" holes were then drilled into the 1-1/2" flange for guy lines.