I was reading some recipes for Eccles cakes, which are a pastry from England.

http://www.hwatson.force9.co.uk/cook...ing/eccles.htm

They call for "currants" and "chopped mixed peel".
Now, I assume "currants" is just another word for raisins, but I'm unsure of
the latter ingredient. Does this imply already prepackaged preserved and/or
candied peel, or would I actually grate the peel from fresh citrus fruit? And
if it's preserved peel, would most supermarkets carry it? Thanks in advance
for your help!