After my start on this idea I did change the centre as you can see below. I wanted this to be a design that could be useful for any teacher who wanted to teach a few advanced ideas.
I think you'll agree that it looks like two simple rounds. Well, sorry, it isn't two rounds - well, it is sort of but it's worked in one 'hit'.
I've sort of 'stolen' the middle out of the roundabout motif (but changed it slightly) and used another idea from here to make this little motif. OK, it needed a bit of fiddling around with to get it as I really wanted it but in the end I'm pleased with it.