[sheerwater]

I'd go for the flame trap/manifold nozzle again just to make sure. In order of my experience (and I know you have tried some of them) is
Cam seal, rocker cover gasket, crank seal. The one not mentioned is a failing head gasket !!!! A common leak however is the rocker cover at the front camshaft bearing. The camshaft bearing/ oil seal housing sometimes needs a little goo as it is slid in. Oil can seep here because its under pressure to the cam. Also when you put the rocker cover gasket on did you put some goo into the sharp corners as it can weep here. These leaks on the front are always a B*!!!! to find. Cheers Nigel