As close an overlay as i can manage, the most obvious thing to me is the difference in your stone 6.
http://i47.tinypic.com/f2u1oz.jpg

Night Roy.[/quote]

With the fallen "Back stone" as a supporting stone. Apologies for the out of scale capstone. (Wine o clock, hic)
http://i45.tinypic.com/2i1jnys.jpg

Also why is there a Moi in profile guarding the entrance ? :P[/quote]

That looks like a portal dolmen .