Hi Steve,
I believe you are right, I'm sure there are few Mk4 sitting around in someone's shed... it's just hard to find them. I had a look at the Bushbaby/Explorer and I really like it, but as you said they are really rare here in Oz.
As for the Aeropup, I had a good look at it and for multiple reason I decided that does not suit me.
I'm just wondering where are all the skyfox gone? I was used to see one or two for sale each month, now I can't find even one.