I have a 1996 1.6 K series Super Sport with the unattractive black plastic (Metro?) fuel filler cap. I'd like to replace it with an aero type. Caterham sell one at £165.70 plus £10 postage, what I find very annoying is they then add 20% VAT to the postage! (postage doesn't attract VAT) A total of £177.70. I only need the cap and gasket part, not the whole assembly which I already have. Has anyone sourced a suitable cap, locking or non locking is fine?