The old coupe is looking good Paul, very nice rebuild.
To clean up the water bottles try this trick I use to clean up old yellowed Lego parts.
http://www.brothers-brick.com/2009/0...look-new-news/
I don't know what type of plastic the bottle is made of but its worth a go, some parts I have done have taken up to 2 weeks under a light to get clean but the results are amazing.