Hi Elias
See the threads started in the horary section. The birthdates appear in the 'poisoned spy' thread.. I have replied to this because as you were writing I was trying to sort out which chart 'fits' best. I have looked at progressions, synastry with the UK chart, astrocartography and midpoints, fixed stars etc. It is neck and neck really. In the 30 Aug his natal Sun=MA/SA progressed Venus is at Algol and a million other ticks for this one, however in the Dec chart Uranus is squaring his Sun and the midpoint that could seal it is NE=MA/SA - this means a mysterious death and death through poisoning. He was also known to be sporty, a general feature of Sags but obviously not exclusively. Also the tr moon was trine his Neptune at the time he was poisoned. That said in the 30 aug chart his pr Sun is sq the UK moon and his pr Mars is conjoining Uk Jupiter - diplomatic wars
I would, however, not definitively side with any as if you look at them all, there is a case for all three! As Draco said, this is the kind of intrigue you would expect with the birthdata of a spy!
Sorry I can't be of more help.