Looking to replace what I think is called a coil bushing and mounting

The window sashes in our bedroom have all stopped working - the sashes drop like a guillotine when you let go. The sashes weigh about 19.8 lbs each; I have previously bought replacement coil springs (5 lbs, 4 per window, same as originally installed), but for some reason the springs got tangled up in the channel. I suspect this is due to sticky shoes, so I've bought new ones, but for good measure I've decided to replace the bushings and their mounts as well.
Issue: I can't find the same part. I've uploaded a picture; its dimensions are 1.25" w x 1 13/32" h x 19/32" d. The outer diameter of the ring is 23/32". At a guess, a 15-150S might work,  but it doesn't have a separately rotating ring as my existing ones do. What part do you recommend to replace the part in the photo? Thanks.

Thank you! I wondered if those might be designed to work together. I'll go ahead and order them.