Kenny,
Yes, it was my first experience of working with Calibre recipes. I was encouraged by Daffy4U in another thread (
https://www.mobileread.com/forums/showthread.php?t=65367). He directed me to
http://calibre-ebook.com/user_manual/news.html, which gave me a start.
But I have to say that, so far, it's been more trial-and-error than deep understanding. I assembled the actual feeds easily enough, but I had some difficulty in getting rid of all the extraneous junk at the start and end of each article - although I got there in the end.
Maybe I need to learn Python.