Hi , thanks for your response, I have managed to get it to work (ish) but I'm not sure what I did. It definitely wasn't anything in the help documentation which I read so thoroughly I think I know it by heart.
I think I had to edit the form layout to include an ID (even thought I couldn't get the Tabs to do what I need)
I left the ID HTTP parameter field blank, and didn't rename the Parameter.
The only issue I have left is that the edit form shows a too comprehensive edit ribbon (see screenshot) Is there a way to reduce the number of options available to just the standard?
thanks