I'll look into winmerge - thanks.
my site (under development with just some sample test products) is http://www.thegiftshop.tv/index.php
This was from a purchased template, and have added:
CKEditor
Convert to UK Dates
Products with attributes
Dropship Core (though not actually used)
CEON SEO url
Captcha
...have also made many little 'tweaks' to code to display as I want.

I would add that I have been back to check the Demo of the purchased template and that also DOES NOT show the attribute choice in cart.