So with the AFM mixture screw all the way in I can get it to idle. Still hunts a little (between about 875-925) but then it did before. What I now have, though, is a dull background noise that sounds like backfiring at idle. Very faint noise though.
I’ve also see this, which suggests that with 60g on the flap it should not move. 60g is quite a lot still isn’t it?! Mine is very freely moving!