Just to repeat. Send me your postal address and, provided it's in the UK, I will send you a sample of the 303 Cleaner and Protectant to try FOC!.
Dilute the cleaner in water to about a ltre and spray on. Use hot water if the RIB tubes are particularly dirty. Once clean use the 303 protectant to give a "like new" finish that is protected against UV fade (when used regularly… ie you will eventually have to buy some more…… I hope!)
303 is envirionmentally safe and you can wash vegetables in it diluted or use it neat to degrease an oil tanker! and it will degrease an engine!
The product has been endorsed by Henshaws by the MD Mr David Brittell no less... any queries feel free to get in touch.
RIB's can look beautiful again, believe me
happy to help