Had no idea there was a Headblade London? or Headblade anything?.
I have always just spoken direct to the customer service at headblade.com and they are awesome
You'll need adapters for the sensor blades but the sensor blades I have found on testing don't work as well as the Headblade 4blade cartridges that come with the ATX, so I wouldn't bother.
Best email headblade.com and they'll sort it all out for you and just buy direct from them, you also will get a discount if you buy as a member of this site by clicking on their banner