Gliders for old Harrison Drape track (Eskbank EH22)

Does anyone happen to have any of these gliders for an old Harrison Drape curtain track? They're tiny: approx 18mm long and the round bit at the top which goes into the channel on the track is 6mm in diameter. It'd save me junking a perfectly good track for the sake of replacing c20 perished gliders.
I've scoured the internet and taken advice from curtain track experts - the track was discontinued 20 yrs ago and the gliders are no longer available.