Series 3 seat frames/runners

Is it me or are seat frames and runners for a series 3 like hens teeth to find? Am I missing a trick? I'm changing the disco seats for the standard series 3 seats which I intend to get from Paddock. I've found 1 set on eBay at the minute, does anyone know anywhere else I could get some from? Without them I'm stuffed as I don't fit with the disco seats in.