

I purchased a spare pair from a breaking Prelude through eBay and got them refurbished with dark red webbing. This allowed me to continue using my car with my original seatbelts fitted. As I never fitted the replacements before they were refurbished, I don't know how well they were retracting but I would assume they suffered a similar problem.

(It's actually a little darker in real life)
It's not clear if any kind of re-tensioning was required to fix their retractile dysfunction. When I dropped off the seatbelts, I was told that replacement webbing and cleaning up the contact areas usually fixes any slow retracting. But whatever, they now retract correctly.
The work was carried out by FDTS Ltd in West Byfleet, Surrey (http://fdts-seatbelts.co.uk). Price was £91.20 including VAT for the pair to be refurbished with Indian Red webbing (code = QI). As I live about 25 - 30 miles away, I dropped them off and collected in person rather than paying for postage. This also allowed me to browse their wide range of colours and choose one that I liked.