Not sure if Karo is the same as golden syrup, but the latter is made by the Tate & Lyle group of companies and they have several websites for subsidiaries and associates worldwide (where you might get info on supplies) at http://www.tate-lyle.co.uk/enquire.html. Golden syrup is wonderful on hot porage (oatmeal).
Swiss roll=jelly roll and the tin (10 inches x 12 inches) is a baking tin of this size with low (less than 1 inch) high sides for making...swiss roll. It must have sides 'cos otherwise the mixture would run off. Ooh, what a messy oven!
Now, back to the slices (nice one Angel!)