>>>>You might want to look into how attributes can be used to make added properties available in the Properties window....

Already doing this, and it is very helpful. Thank you.

>>>>Glad it helped. I'd recommend the Apress 'Pro .Net 2.0 Windows Forms and Custom Controls in C#' book for a good grounding in this. There are three good chapters on 'Custom Controls','Derived Controls' and 'Design Time Support for Custom Controls'

I have this book and I read it entirely in November/December when I was planning out the development of this system; excellent book but I've forgotten much of what I read in it. It's open right in front of me now.

Again thank you for clearing things up.