Thanks cabriolet.
Fitted the valve on the line in to the filter, at the same time I bypassed the black box heating element,Seems these only heat fuel whilst the engine is running. so not a lot of point to it really, and they have a reputation for letting air in.
Still took half a dozen turns this morning though! not really made a difference, apart from the idle which does seem a lot smoother. Not taken it for a run yet.
One thing I have noticed...........The primer ( original) never gets hard......... Never......... 50 pumps and its still possible to depress it halfway......so somethings out of order. But starts and runs well...
replacement filter head again next, tried an oem one and binned it...seen one on the bay that looks like a ford original , new stock going cheap.
Would be interested in what you can tell me about the pump though. its not the bosch one and appears to have no electrics to it.