Ebay is surprisingly good, you can get some cheap stuff thats in good nick. You would probably have to go on the uk ebay though to get any spares.
Other websites i have used and have found to be good are:
http://www.minispares.com/
http://www.minispeed.co.uk/classic/
http://www.minisport.com/classic-mini-shop/products.html
http://www.moss-europe.co.uk/MossUK/Browse...yID=ClassicMini
And finally this is a brillant forum:
http://www.minifinity.com
Your mini looks like a fine example. It looks very neat, can't see one bit of cosmetic rust. Well Done.